Natural composite biomaterials are good structural supports for bone cells to regenerate lost bone. Here, we report that a chitosan-collagen composite film accelerated osteoblast proliferation, ...differentiation and matrix mineralization in MC3T3-E1 cells. Intriguingly, we observed that the film enhanced the phosphorylation of Erk1/2. We showed that the chitosan-collagen composite film increased the transcriptional activity of Runx2, which is an important factor regulating osteoblast differentiation downstream of phosphorylated Erk1/2. Consistent with this observation, we found that the chitosan-collagen composite film increased the expression of osteoblastic marker genes, including Type I Collagen and Runx2 in MC3T3-E1 cells. We conclude that this film promoted osteoblast differentiation and matrix mineralization through an Erk1/2-activated Runx2 pathway. Our findings provide new evidence that chitosan-collagen composites are promising biomaterials for bone tissue engineering in bone defect-related diseases.
Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA ...X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (
Furlan and Rougeulle, 2016
;
Maduro et al., 2016
). These RNAs are believed to be transcribed by the approximately 98–99% non-coding regions of the human genome (
Derrien et al., 2012
;
Fu, 2014
;
Montalbano et al., 2017
;
Slack and Chinnaiyan, 2019
), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (
Ma et al., 2013
;
Devaux et al., 2015
;
St Laurent et al., 2015
;
Chen, 2016
;
Quinn and Chang, 2016
;
Richard and Eichhorn, 2018
;
Connerty et al., 2020
). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (
Cao et al., 2018
). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (
Jiang W. et al., 2018
;
Zhou et al., 2019a
). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000–20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (
Brown et al., 1992
;
Debrand et al., 1998
;
Kay, 1998
;
Lee et al., 2013
;
da Rocha and Heard, 2017
;
Yang Z. et al., 2018
;
Brockdorff, 2019
). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (
Liu et al., 2018b
;
Deng et al., 2019
;
Dinescu et al., 2019
;
Mutzel and Schulz, 2020
;
Patrat et al., 2020
;
Wang et al., 2020a
). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in
Table 1
. It was also believed that lncRNA Xist (
Chaligne and Heard, 2014
;
Yang Z. et al., 2018
) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in
Table 2
. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.
Beijing is severely affected by land subsidence, and rapid urbanisation and building construction might accelerate the land subsidence process. Based on 39 Envisat Advanced Synthetic Aperture Radar ...(ASAR) images acquired between 2003–2010, 55 TerraSAR-X images acquired between 2010–2016, and urban building information, we analysed the relationship between land subsidence and buildings at the regional, block, and building scales. The results show that the surface displacement rate in the Beijing urban area ranged from −109 mm/year to +13 mm/year between 2003–2010, and from −151 mm/year to +19 mm/year between 2010–2016; two subsidence bowls were mainly distributed in the eastern part of the Chaoyang District. The displacement rate agreed well with the levelling measurements, with an average bias of less than six mm/year. At the regional scale, the spatial pattern of land subsidence was mainly controlled by groundwater extraction, compressible layer thickness, and geological faults. Subsidence centres were located in the area around ground water funnels with a compressible layer depth of 50–70 m. The block-scale analysis demonstrated a clear correlation between the block construction age and the spatial unevenness of subsidence. The blocks constructed between 1998–2005 and after 2005 showed considerably more subsidence unevenness and temporal instability than the blocks constructed before 1998 during both time periods. The examination of the new blocks showed that the spatial unevenness increased with building volume variability. For the 16 blocks with a high building volume, variability, and subsidence unevenness, the building-scale analysis showed a positive relationship between building volume and settlement in most blocks, although the R2 was lower than 0.5. The results indicate that intense building construction in urban areas could cause differential settlement at the block scale in Beijing, while the settlement of single buildings could be influenced by the integrated effects of building volume, foundation structures, and the hydrogeological background.
Tea plants that have a large leaf area mainly suffer from heavy metal accumulation in the above-ground parts through foliar uptake. With the world rapid industrialization, this pollution in tea is ...considered a crucial challenge due to its potential health risks. The present study proposes an innovative approach based on visible and near-infrared (Vis-NIR) spectroscopy coupled with chemometrics for the characterization of tea chemical indicators under airborne lead stress, which can be performed fast and in situ. The effects of lead stress on chemical indicators and accumulation in leaves of the two tea varieties at different time intervals and levels of treatment were investigated. In addition, changes in cell structure and leaf stomata were monitored during foliar uptake of aerosol particles by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The spectral variation was able to classify the tea samples into the Pb treatment groups through the linear discriminant analysis (LDA) model. Two machine learning techniques, namely, partial least squares (PLS) and radial basis function neural network (RBFNN), were evaluated and compared for building the quantitative determination models. The RBFNN models combined with correlation-based feature selection (CFS) and PLS data compression methods were used to optimize the prediction performance. The results demonstrated that the PLS–RBFNN as a non-linear model outperformed the PLS model and provided the R-value of 0.944, 0.952, 0.881, 0.937, and 0.930 for prediction of MDA, starch, sucrose, fructose, glucose, respectively. It can be concluded that the proposed approach has strong application potential in monitoring the quality and safety of plants under airborne heavy metal stress.
Display omitted
•Effects of Pb pollution on tea quality and safety were explored by Vis-NIR spectra.•Leaf microstructure changes during uptake of atmospheric aerosols were studied.•Spectral differences can distinguish samples into airborne Pb treatment groups.•PLS–RBFNN performed better than PLS in predicting the chemical indicators of tea.•The spectra coupled with nonlinear models yielded high accuracy for Pb monitoring.
Metabolic engineering of cyanobacteria has received much attention as a sustainable strategy to convert CO
2
to various longer carbon chain fuels. Pinene has become increasingly attractive since ...pinene dimers contain high volumetric energy and have been proposed to act as potential aircraft fuels. However, cyanobacteria cannot directly convert geranyl pyrophosphate into pinene due to the lack of endogenous pinene synthase. Herein, we integrated the gene encoding
Abies grandis
pinene synthase into the model cyanobacterium
Synechococcus
sp. PCC 7002 through homologous recombination. The genetically modified cyanobacteria achieved a pinene titer of 1.525 ± 0.l45 mg L
−1
in the lab-scale tube photobioreactor with CO
2
aeration. Specifically, the results showed a mixture of
α
- and
β
-pinene (∼33:67 ratio). The ratio of
β
-pinene in the product was significantly increased compared with that previously reported in the engineered
Escherichia coli
. Furthermore, we investigated the photoautotrophic growth performances of
Synechococcus
overlaid with different concentrations of dodecane. The work demonstrates that the engineered
Synechococcus
is a suitable potential platform for
β
-pinene production.
A novel graphene oxide (GO)-based carrier was fabricated for the controlled release of Benazepril (BENA). Freeze dried samples of GO–BENA carrier were prepared for controlled drug release at ...different pHs (pH = 2, 7, and 10) and release kinetics indicate BENA desorption from GO is by Fickian diffusion. The BENA yield from the carrier amounted to ~55% of the adsorbed material in a strongly acidic medium after 50 h. Binding fractions of BENA to 10 mg/L GO was determined for different solution concentrations of the drug. In vitro assays of cell proliferation (WST-1 kit), cell structural integrity (LDH kit) and flow cytometric indicators of necrosis in three different cell lines (CACO-2, SGC-7901, and primary mouse hepatic fibroblast) all demonstrated that the GO carrier had a good biocompatibility. The pH-dependent release sensitivity of the GO-based carrier suggests that it is a potential candidate for use in the controlled release of drugs in the acidic environment of the stomach.
Neural stem cells (NSCs) have the ability to differentiate into neurons, astrocytes and oligodendrocytes. They are self-renewing and sufficient to provide large amounts of brain tissue cells. NSCs ...have promising application prospects for the treatment of central nervous system diseases. Spider toxins are important tools for use in neurobiology and neuropharmacology. In this study, a Cell Counting Kit (CCK-8), immunofluorescence staining, real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting were used to qualitatively and quantitatively analyse the effects of different concentrations (1, 10 and 20 μg/mL) of Chilobrachys jingzhao crude venom on the proliferation and differentiation of C17.2 cells in vitro. At low concentrations, C. jingzhao crude venom did not significantly inhibit the proliferation of NSCs; however, the highest concentration of 20 μg/mL partially inhibited the NSC proliferation. In the differentiation medium, addition of C. jingzhao crude venom effectively promoted the differentiation of NSCs towards neuronal cells, with a final concentration of 10 μg/mL having the most obvious effect. These results suggest that C. jingzhao crude venom exerts a regulatory effect on the proliferation and differentiation of C17.2 cells. Therefore, spider venom can be used as an 'ammunition library' to find factors that regulate the proliferation and differentiation of NSCs, laying the groundwork for the application of NSCs in the treatment of central nervous system diseases.
Rapid nondestructive determination of the moisture content of tea leaves is the basis of intelligent control in tea processing. Visible and near infrared (Vis/NIR) spectroscopy can detect the ...fundamental vibrations of hydrogen group (O–H) in the organic molecules, and has become one of the most commonly used methods for rapid determination of the moisture content of tea leaves. However, the established spectral model often fails to predict new samples of different varieties or batches, and then it will limit the wide application of this technology. Hence, improvement in the model and removing the impact of these samples variation on the determination model become a key issue for quality control during tea processing. In this study, tea samples of nine batches from three varieties were adopted to verify the performance of model transfer in improving the generalization of spectral models, it is worth noting that the moisture content distribution of different varieties samples is obviously different. It can be found that spectral profile difference of the three batches of tea samples for each variety was effectively eliminated by model transfer. The prediction ability of the PLSR model was improved by correcting the spectra of the tested batches and varieties of tea leaves to solve the problem induced by sample differences. The determination model developed based on the variety of “Longjing” was successfully transferred to the other two varieties of “Wuniuzao” and “Yingshuang”, and the Rp2 were improved from 0.4343 to 0.2066 to 0.7595 and 0.6376, respectively by using DS algorithm comparing with un-transferred models. This study demonstrated that the proposed model transfer strategy by correcting the spectral data could be a robust technique for the rapid detection of the moisture content in different types of tea leaves and lay a basis for industrial application.
•The reason for the difference in water loss rate of differnet tea varieties was revealed.•Vis/NIR spectroscopy is appropriate for determining the moisture content of tea leaves.•Model transfer algorithm was developed to eliminate spectral differences from different varieties and batches.
Recently, there are significant advancements in learning-based image compression methods surpassing traditional coding standards. Most of them prioritize achieving the best rate-distortion ...performance for a particular compression rate, which limits their flexibility and adaptability in various applications with complex and varying constraints. In this work, we explore the potential of resolution fields in scalable image compression and propose the reciprocal pyramid network (RPN) that fulfills the need for more adaptable and versatile compression. Specifically, RPN first builds a compression pyramid and generates the resolution fields at different levels in a top-down manner. The key design lies in the cross-resolution context mining module between adjacent levels, which performs feature enriching and distillation to mine meaningful contextualized information and remove unnecessary redundancy, producing informative resolution fields as residual priors. The scalability is achieved by progressive bitstream reusing and resolution field incorporation varying at different levels. Furthermore, between adjacent compression levels, we explicitly quantify the aleatoric uncertainty from the bottom decoded representations and develop an uncertainty-guided loss to update the upper-level compression parameters, forming a reverse pyramid process that enforces the network to focus on the textured pixels with high variance for more reliable and accurate reconstruction. Combining resolution field exploration and uncertainty guidance in a pyramid manner, RPN can effectively achieve spatial and quality scalable image compression. Experiments show the superiority of RPN against existing classical and deep learning-based scalable codecs. Code will be available at https://github.com/JGIroro/RPNSIC .
Jingzhaotoxin-34 (JZTX-34) is a 35-residue polypeptide from the venom of Chinese tarantula
Chilobrachys jingzhao. Our previous work reported its full-length cDNA sequence encoding a precursor with 87 ...residues. In this study we report the protein expression and biological function characterization. The toxin was efficiently expressed by the secretary pathway in yeast. Under whole-cell patch-clamp mode, the expressed JZTX-34 was able to inhibit tetrodotoxin-sensitive (TTX-S) sodium currents (IC
50
∼
85
nM) while having no significant effects on tetrodotoxin-resistant (TTX-R) sodium currents on rat dorsal root ganglion neurons. The inhibition of TTX-S sodium channels was completely reversed by strong depolarization (+120
mV). Toxin treatment altered neither channel activation and inactivation kinetics nor recovery rate from inactivation. However, it is interesting to note that in contrast to huwentoxin-IV, a recently identified receptor site-4 toxin from
Ornithoctonus huwena venom, 100
nM JZTX-34 caused a negative shift of steady-state inactivation curve of TTX-S sodium channels by approximately 10
mV. The results indicated that JZTX-34 might inhibit mammalian sensory neuronal sodium channels through a mechanism similar to HWTX-IV by trapping the IIS4 voltage sensor in the resting conformation, but their binding sites should not overlay completely.
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