Release of miR-29 Target Laminin C2 Improves Skin Repair.

miRNAs are small noncoding RNAs that regulate mRNA targets in a cell-specific manner. miR-29 is expressed in murine and human skin, where it may regulate functions in skin repair. Cutaneous wound healing model in miR-29a/b1 gene knockout mice was used to identify miR-29 targets in the wound matrix, where angiogenesis and maturation of provisional granulation tissue was enhanced in response to genetic deletion of miR-29. Consistently, antisense-mediated inhibition of miR-29 promoted angiogenesis in vitro by autocrine and paracrine mechanisms. These processes are likely mediated by miR-29 target mRNAs released upon removal of miR-29 to improve cell-matrix adhesion. One of these, laminin (Lam)-c2 (also known as laminin γ2), was strongly up-regulated during skin repair in the wound matrix of knockout mice. Unexpectedly, Lamc2 was deposited in the basal membrane of endothelial cells in blood vessels forming in the granulation tissue of knockout mice. New blood vessels showed punctate interactions between Lamc2 and integrin α6 (Itga6) along the length of the proto-vessels, suggesting that greater levels of Lamc2 may contribute to the adhesion of endothelial cells, thus assisting angiogenesis within the wound. These findings may be of translational relevance, as LAMC2 was deposited at the leading edge in human wounds, where it formed a basal membrane for endothelial cells and assisted neovascularization. These results suggest a link between LAMC2, improved angiogenesis, and re-epithelialization.

Construction of an Electron Capture and Transfer Center for Highly Efficient and Selective Solar-Light-Driven CO2 Conversion.

Exploring high-efficiency photocatalysts for selective CO2 reduction is still challenging because of the limited charge separation and surface reactions. In this study, a noble-metal-free metallic VSe2 nanosheet was incorporated on g-C3N4 to serve as an electron capture and transfer center, activating surface active sites for highly efficient and selective CO2 photoreduction. Quasi in situ X-ray photoelectron spectroscopy (XPS), soft X-ray absorption spectroscopy (sXAS), and femtosecond transient absorption spectroscopy (fs-TAS) unveiled that VSe2 could capture electrons, which are further transferred to the surface for activating active sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations revealed a kinetically feasible process for the formation of a key intermediate and confirmed the favorable production of CO on the VSe2/PCN (protonated C3N4) photocatalyst. As an outcome, the optimized VSe2/PCN composite achieved 97% selectivity for solar-light-driven CO2 conversion to CO with a high rate of 16.3 µmol·g-1·h-1, without any sacrificial reagent or photosensitizer. This work offers new insights into the photocatalyst design toward highly efficient and selective CO2 conversion.

Remote Synergy between Heterogeneous Single Atoms and Clusters for Enhanced Oxygen Evolution.

Integrating single atoms and clusters into one system is a novel strategy to achieve desired catalytic performances. Compared with homogeneous single-atom cluster catalysts, heterogeneous ones combine the merits of different species and therefore show greater potential. However, it is still challenging to construct single-atom cluster systems of heterogeneous species, and the underlying mechanism for activity improvement remains unclear. In this work, we developed a heterogeneous single-atom cluster catalyst (ConIr1/N-C) for efficient oxygen evolution. The Ir single atoms worked in synergy with the Co clusters at a distance of about 8 Å, which optimized the configuration of the key intermediates. Consequently, the oxygen evolution activity was significantly improved on ConIr1/N-C relative to the Co cluster catalyst (Con/N-C), exhibiting an overpotential lower by 107 mV than that of Con/N-C at 10 mA cm-2 and a turnover frequency 50.9 times as much as that of Con/N-C at an overpotential of 300 mV.

Study on the Mechanism of Lipid Peroxidation Induced by Carbonate Radicals.

Based on the reported research, hydroxyl radicals can be rapidly transformed into carbonate radicals in the carbonate-bicarbonate buffering system in vivo. Many of the processes considered to be initiated by hydroxyl radicals may be caused by carbonate radicals, which indicates that lipid peroxidation initiated by hydroxyl radicals can also be caused by carbonate radicals. To date, theoretical research on reactions of hydrogen abstraction from and radical addition to polyunsaturated fatty acids (PUFAs) of carbonate radicals has not been carried out systematically. This paper employs (3Z,6Z)-nona-3,6-diene (NDE) as a model for polyunsaturated fatty acids (PUFAs). Density functional theory (DFT) with the CAM-B3LYP method at the 6-311+g(d,p) level was used to calculate the differences in reactivity of carbonate radicals abstracting hydrogen from different positions of NDE and their addition to the double bonds of NDE under lipid solvent conditions with a dielectric constant of 4.0 (CPCM model). Grimme's empirical dispersion correction was taken into account through the D3 scheme. The energy barrier, reaction rate constants, internal energy, enthalpy and Gibbs free energy changes in these reactions were calculated With zero-point vibrational energy (ZPVE) corrections. The results indicated that carbonate radicals initiate lipid peroxidation primarily through hydrogen abstraction from diallyl carbon atoms. The reaction of hydrogen abstraction from diallyl carbon atoms exhibits the highest reaction rate, with a reaction rate constant approximately 43-fold greater than the second-ranked hydrogen abstraction from allyl carbon atoms. This process has the lowest energy barrier, internal energy, enthalpy, and Gibbs free energy changes, indicating that it is also the most spontaneous process.

Neighbouring Synergy in High-Density Single Ir Atoms on CoGaOOH for Efficient Alkaline Electrocatalytic Oxygen Evolution.

The catalytic performance of single-atom catalysts was strictly limited by isolated single-atom sites. Fabricating high-density single atoms to realize the synergetic interaction in neighbouring single atoms could optimize the adsorption behaviors of reaction intermediates, which exhibited great potential to break performance limitations and deepen mechanistic understanding of electrocatalysis. However, the catalytic behavior governed by neighbouring single atoms is particularly elusive and has yet to be understood. Herein, we revealed that the synergetic interaction in neighbouring single atoms contributes to superior performance for oxygen evolution relative to isolated Ir single atoms. Neighbouring single atoms was achieved by fabricating high-density single atoms to narrow the distance between single atoms. Electrochemical measurements demonstrated that the Nei-Ir1/CoGaOOH with neighbouring Ir single atoms exhibited a low overpotential of 170 mV at a current density of 10 mA cm-2, and long-durable stability over 2000 h for oxygen evolution. Mechanistic studies revealed that neighbouring single atoms synergetic stabilized the *OOH intermediates via extra hydrogen bonding interactions, thus significantly reducing the reaction energy barriers, as compared to isolated Ir single atoms. The discovery of the synergetic interaction in neighbouring single atoms could offer guidance for the development of efficient electrocatalysts, thus accelerating the world's transition to sustainable energy.

Efficient Suppression of Dendrites and Side Reactions by Strong Electrostatic Shielding Effect via the Additive of Rb2 SO4 for Anodes in Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention due to their low cost and environmental friendliness. However, the rampant dendrite growth and severe side reactions during plating/stripping on the surface of zinc (Zn) anode hinder the practicability of AZIBs. Herein, an effective and non-toxic cationic electrolyte additive of Rb2 SO4 is proposed to address the issues. The large cation of Rb+ is preferentially adsorbed on the surface of Zn metal to induce a strong shielding effect for realizing the lateral deposition of Zn2+ ions along the Zn surface and isolating water from Zn metal to effectively inhibit side reactions. Consequently, the Zn||Zn symmetric cell with the addition of 1.5 mm Rb2 SO4 can cycle more than 6000 h at 0.5 mA cm-2 /0.25 mAh cm-2 , which is 20 times longer than that without Rb2 SO4 . Besides, the Zn||Cu asymmetric cell with Rb2 SO4 achieves a very high average Coulombic efficiency of 99.16% up to 500 cycles. Moreover, the electrolyte with Rb2 SO4 well matches with the VO2 cathode, achieving high initial capacity of 412.7 mAh g-1 at 5 A g-1 and excellent cycling stability with a capacity retention of 71.6% at 5 A g-1 after 500 cycles for the Zn//VO2 full cell.

METTL14 represses osteoclast formation to ameliorate osteoporosis via enhancing GPX4 mRNA stability.

Excessive bone resorption by osteoclasts results in the development of multiple bone disorders including osteoporosis. This study aimed to explore the biological function of methyltransferase-like14 (METTL14) in osteoclast formation, as well as its related mechanisms. Expression levels of METTL14, GPX4 and osteoclast-related proteins TRAP, NFATc1, c-Fos were detected by qRT-PCR and Western blotting. The osteoporosis model was established in mice by bilateral ovariectomy (OVX). Bone histomorphology was determined by micro-CT and H&E staining. NFATc1 expression in bone tissues was determined by immunohistochemical staining. Proliferation of primary bone marrow macrophages cells (BMMs) was assessed by MTT assay. Osteoclast formation was observed by TRAP staining. The regulatory mechanism was evaluated by RNA methylation quantification assay, MeRIP-qPCR, dual luciferase reporter assay, and RIP, respectively. METTL14 was down-regulated in the serum samples of postmenopausal osteoporotic women, which was positively associated with bone mineral density (BMD). Osteoclast formation was promoted in OVX-treated METTL14+/- mice as compared with wild-type littermates. Conversely, METTL14 overexpression repressed RANKL-induced osteoclast differentiation of BMMs. Mechanistically, METTL14-mediated m6A modification post-transcriptionally stabilized glutathione peroxidase 4 (GPX4), with the assistance of Hu-Antigen R (HuR). Finally, GPX4 depletion-mediated osteoclast formation in BMMs could be counteracted by METTL14 or HuR overexpression. Collectively, METTL14 inhibits osteoclastogenesis and bone resorption via enhancing GPX4 stability through an m6A-HuR dependent mechanism. Therefore, targeting METTL14 might be a novel promising treatment strategy for osteoporosis.

The Integration of Genome-Wide DNA Methylation and Transcriptomics Identifies the Potential Genes That Regulate the Development of Skeletal Muscles in Ducks.

DNA methylation is a pivotal epigenetic regulatory mechanism in the development of skeletal muscles. Nonetheless, the regulators responsible for DNA methylation in the development of embryonic duck skeletal muscles remain unknown. In the present study, whole genome bisulfite sequencing (WGBS) and transcriptome sequencing were conducted on the skeletal muscles of embryonic day 21 (E21) and day 28 (E28) ducks. The DNA methylation pattern was found to fall mainly within the cytosine-guanine (CG) context, with high methylation levels in the intron, exon, and promoter regions. Overall, 7902 differentially methylated regions (DMRs) were identified, which corresponded to 3174 differentially methylated genes (DMGs). By using integrative analysis of both WGBS with transcriptomics, we identified 1072 genes that are DMGs that are negatively associated with differentially expressed genes (DEGs). The gene ontology (GO) analysis revealed significant enrichment in phosphorylation, kinase activity, phosphotransferase activity, alcohol-based receptors, and binding to cytoskeletal proteins. The Kyoto Encyclopedia of Genes and Genomes (KEGGs) analysis showed significant enrichment in MAPK signaling, Wnt signaling, apelin signaling, insulin signaling, and FoxO signaling. The screening of enriched genes showed that hyper-methylation inhibited the expression of Idh3a, Got1, Bcl2, Mylk2, Klf2, Erbin, and Klhl38, and hypo-methylation stimulated the expression of Col22a1, Dnmt3b, Fn1, E2f1, Rprm, and Wfikkn1. Further predictions showed that the CpG islands in the promoters of Klhl38, Klf2, Erbin, Mylk2, and Got1 may play a crucial role in regulating the development of skeletal muscles. This study provides new insights into the epigenetic regulation of the development of duck skeletal muscles.

Copper Hexacyanoferrate Solid-State Electrolyte Protection Layer on Zn Metal Anode for High-Performance Aqueous Zinc-Ion Batteries.

Zinc (Zn) metal possesses broad prospects as an anode for aqueous zinc-ion batteries (AZIBs) due to its considerable theoretical capacity of 820 mAh g-1 . However, the Zn anode suffers from dendrite growth and side reactions during Zn stripping/plating. Herein, a Prussian blue analog of copper hexacyanoferrate (CuHCF) with a 3D open structure and rich polar groups (CN) is coated on Zn foil as a solid-state electrolyte (SSE) protection layer to protect the Zn anode. The CuHCF protection layer possesses low activation energy of 26.49 kJ mol-1 , the high ionic conductivity of 7.6 mS cm-1 , and a large Zn2+ transference number of 0.74. Hence, the Zn@CuHCF||Zn@CuHCF symmetric cell delivers high cycling stability over 1800 h at 5 mA cm-2 , an excellent depth of discharge of 51.3%, and the accumulative discharge capacity over 3000 mAh cm-2 . In addition, the Zn//Ti@CuHCF asymmetric cell achieves the coulombic efficiency (CE) of 99.87% after 2000 cycles. More importantly, the Zn@CuHCF//V2 O5 full cell presents outstanding capacity retention of 87.6% at 10 A g-1 after 3000 cycles. This work develops a type of material to form an artificial protection layer for high-performance AZIBs.

Knockdown of Tet2 Inhibits the Myogenic Differentiation of Chicken Myoblasts Induced by Ascorbic Acid.

Ascorbic acid (also called Vitamin C, VC) strengthens the function of Tets families and directly increases DNA demethylation level to affect myogenic differentiation. However, the precise regulatory mechanism of DNA methylation in chicken myogenesis remains unclear. Results of present study showed that the mRNA expression of MyoD significantly decreased and MyoG and MyHC increased in myoblasts treated with 5 µM 5-azacytidine (5-AZA) and 5 µM VC (p < 0.05). Results also indicated the formation of myotubes was induced by 5-AZA or VC, but this effect was attenuated after knockdown of Tet2. In addition, the protein expression of TET2, DESMIN and MyHC was remarkable increased by the addition of 5-AZA or VC, and the upregulation was inhibited after knockdown of Tet2 (p < 0.05). DNA dot blot and immunofluorescence staining results suggested that the level of 5hmC was significantly increased when treated with 5-AZA or VC, even by Tet2 knockdown (p < 0.05). Moreover, 5-AZA and VC reduced the level of dimethylation of lysine 9 (H3K9me2) and trimethylation of lysine 27 of histone 3 (H3K27me3), and this inhibitory effect was eliminated after Tet2 knockdown (p < 0.05). These data indicated that Tet2 knockdown antagonized the increased levels of 5hmC and H3K27me3 induced by 5-AZA and VC, and eventually reduced myotube formation by modulating the expression of genes involved in myogenic differentiation. This study provides insights that epigenetic regulators play essential roles in mediating the myogenic program of chicken myoblasts.

Multi-center investigation of breast reconstruction after mastectomy from Chinese Society of Breast Surgery: A survey based on 31 tertiary hospitals (CSBrS-004).

OBJECTIVE: Multi-center data on the current status and trends of breast reconstruction after mastectomy in China are lacking. Herein, we conducted a cross-sectional survey to investigate the current clinical practice pattern of postmastectomy breast reconstruction among Chinese female patients with breast cancer. METHODS: A standardized questionnaire used to collect information on breast reconstruction among females diagnosed with breast cancer was distributed by 31 members of the Chinese Society of Breast Surgery between January 1, 2018 and December 31, 2018. Information was collected on tumor characteristics, treatment, mesh application, nipple-areola complex (NAC) preservation, postoperative complications, bilateral reconstruction, patient satisfaction and local recurrence. The overall rate of breast reconstruction was assessed, and the characteristics were compared across patient groups with different reconstruction approaches. RESULTS: A total of 1,554 patients underwent breast reconstruction after total mastectomy, with a reconstruction rate of 9.6%. Among them, 1,190 were implant-based, and 262 underwent autologous reconstructions, while 102 cases underwent a combination of both. Patients who underwent implant-based reconstruction were younger than those who received autologous reconstruction (40.1±4.6 vs. 45.0±5.9, P=0.004). Compared to patients with autologous reconstruction, mesh application (25.5% vs. 6.5%), NAC preservation (51.8% vs. 40.5%) and reconstruction failure (1.8% vs. 0) were more frequently reported among those with implant-based reconstruction. There was no significant difference in general satisfaction across three reconstruction approaches, though patients with autologous reconstruction reported the highest aesthetic satisfaction among the three groups (P=0.044). CONCLUSIONS: Implant-based breast reconstruction remains the dominant choice among patients, while autologous reconstruction was associated with higher aesthetic satisfaction. Our multi-center investigation based on the findings of the tertiary hospitals of Chinese Society of Breast Surgery may guide a future series of clinical studies on breast reconstruction in China.

Establishing a new hot electrons transfer channel by ion doping in a plasmonic metal/semiconductor photocatalyst.

A straightforward strategy is developed to improve the injection efficiency of hot electrons in a Ag/TiO2 plasmonic photocatalyst by introducing Fe as a dopant. The Fe dopant energy level formed within the bandgap of TiO2 provides an extra electron transfer channel for transferring the hot electrons induced by plasmonic Ag nanoparticles.

Recognition of Dorsal Hand Vein Based Bit Planes and Block Mutual Information.

The dorsal hand vein images captured by cross-device may have great differences in brightness, displacement, rotation angle and size. These deviations must influence greatly the results of dorsal hand vein recognition. To solve these problems, the method of dorsal hand vein recognition was put forward based on bit plane and block mutual information in this paper. Firstly, the input gray image of dorsal hand vein was converted to eight-bit planes to overcome the interference of brightness inside the higher bit planes and the interference of noise inside the lower bit planes. Secondly, the texture of each bit plane of dorsal hand vein was described by a block method and the mutual information between blocks was calculated as texture features by three kinds of modes to solve the problem of rotation and size. Finally, the experiments cross-device were carried out. One device was used to be registered, the other was used to recognize. Compared with the SIFT (Scale-invariant feature transform, SIFT) algorithm, the new algorithm can increase the recognition rate of dorsal hand vein from 86.60% to 93.33%.

Research on GA-SVM Based Head-Motion Classification via Mechanomyography Feature Analysis.

This study investigated classification of six types of head motions using mechanomyography (MMG) signals. An unequal segmenting algorithm was adopted to segment the MMG signals generated by head motions. Three types of features (time domain, time-frequency domain and nonlinear dynamics) were extracted to construct five feature sets as candidate datasets for classification analysis. Genetic algorithm optimized support vector machine (GA-SVM) was used to classify the MMG signals. Three different kernel functions, different combinations of feature sets, different number of signal channels and training samples were selected for comparative analysis to evaluate the classification accuracy. Experimental results showed that the classifier had the best overall classification accuracy when using the radial basis function (RBF). Any combination of three different types of feature sets guaranteed an average accuracy of over 80%. In the case of the best combination (feature set 2 + 3 + 5), the classification accuracy was up to 88.2%. Using four channels to acquire MMG signal and no less than 60 training samples can assure a satisfactory classification accuracy.

MicroRNA-200c plays an oncogenic role in nasopharyngeal carcinoma by targeting PTEN.

Recent studies suggested that microRNA-200 family microRNAs play critical roles in cancer initiation and metastasis. The underlying mechanism remained elusive. In this study, we show that microRNA-200c is upregulated in nasopharyngeal carcinoma cells. Manipulation of microRNA-200c levels affected cell growth, migration, and invasion in nasopharyngeal carcinoma cell lines. Furthermore, PTEN was identified as a direct target of microRNA-200c. Overexpression of PTEN resulted in similar effects to those of anti-microRNA-200c transfection. In vivo suppression of microRNA-200c level reduced tumor growth in mice. Overall, our data suggest that microRNA-200c plays an oncogenic role in nasopharyngeal carcinoma by targeting PTEN.

Both FOXO3a and FOXO1 are involved in the HGF-protective pathway against apoptosis in endothelial cells.

Hepatocyte growth factor (HGF) was identified as an endogenous tissue protective agent against apoptosis in many cell types. The mechanism by which HGF protects primary endothelial cells (ECs) has not yet been completely elucidated. FOXO1 and FOXO3a, two members of the FOXO family, are the most abundant FOXO isoforms in mature endothelial cells. In this study, we aimed to explore whether FOXO1 and FOXO3a play similar roles in HGF-mediated protection against apoptosis in mature endothelial cells. Our result showed that HGF prevented ECs from oxidative-stress induced apoptosis in part by inducing the phosphorylation of FOXO proteins. FOXO1 and FOXO3a are equally important in this process by regulating the expression of Bim, PUMA, FasL, and TRAIL.

G-CSF promotes the development of hepatocellular carcinoma by activating the PI3K/AKT/mTOR pathway in TAM.

OBJECTIVE: This investigation seeks to elucidate the role of the Granulocyte Colony-Stimulating Factor (G-CSF) in the progression of hepatocellular carcinoma (HCC), as well as the impact of the substance on related signaling pathways within the disease matrix. METHODS: Nude mouse tumor-bearing assay was used to detect tumor progression. Levels of Mannose/CD68 and CD34/Mannose within these samples and the concentrations of Mannose and inducible Nitric Oxide Synthase (iNOS) in macrophages were quantified using immunofluorescence techniques. The angiogenic capability was assessed via tube formation assays, and protein expressions of G-CSF, Vascular Endothelial Growth Factor (VEGF), Transforming Growth Factor-beta (TGF-ß), Matrix Metalloproteinases 2 and 9 (MMP2/9), SH2-containing protein tyrosine phosphatase-2 (SHP-2), phosphorylated PI3K/total PI3K (P-PI3K/t-PI3K), phosphorylated AKT/total AKT (P-AKT/t-AKT), and phosphorylated mTOR/total mTOR (P-mTOR/t-mTOR) were measured through Western Blot analysis in both tumor tissues and macrophages. RESULTS: Administration of G-CSF resulted in a marked augmentation of tumor volume. Macrophage Mannose expression was significantly elevated upon G-CSF treatment, while iNOS levels were conspicuously diminished. G-CSF substantially enhanced the secretion of VEGF, TGF-ß, and MMPs in tumor tissues. Macrophage parameters, following incubation in G-CSF pre-treated conditioned medium, indicated enhanced tube-forming capabilities relative to the control, an effect mitigated by the introduction of specific inhibitors. Furthermore, the G-CSF group exhibited a notable reduction in SHP-2 expression, alongside a substantial elevation in the phosphorylation levels of the PI3K/AKT/mTOR pathway proteins across all tumor-bearing paradigms. CONCLUSION: G-CSF ostensibly facilitates the advancement of hepatocellular carcinoma by activating the PI3K/AKT/mTOR signaling cascade within Tumor-Associated Macrophages (TAM).

Terminal trajectory of HbA1c for 10 years supports the HbA1c paradox: a longitudinal study using Health and Retirement Study data.

Objectives: We aimed to assess the potential time-varying associations between HbA1c and mortality, as well as the terminal trajectory of HbA1c in the elderly to reveal the underlying mechanisms. Design: The design is a longitudinal study using data from the Health and Retirement Study. Setting and participants: Data were from the Health and Retirement Study. A total of 10,408 participants aged ≥50 years with available HbA1c measurements at baseline (2006/2008) were included. Methods: Longitudinal HbA1c measured at 2010/2012 and 2014/2016 were collected. HbA1c values measured three times for their associations with all-cause mortality were assessed using Cox regression and restricted cubic splines. HbA1c terminal trajectories over 10 years before death were analyzed using linear mixed-effect models with a backward time scale. Results: Women constitute 59.6% of the participants with a mean age of 69 years, with 3,070 decedents during the follow-up (8.9 years). The mortality rate during follow-up was 29.5%. Increased mortality risk became insignificant for the highest quartile of HbA1c compared to the third quartile (aHR 1.148, 1.302, and 1.069 for a follow-up of 8.9, 6.5, and 3.2 years, respectively) with a shorter follow-up, while it became higher for the lowest quartile of HbA1c (aHR 0.986, 1.068, and 1.439 for a follow-up of 8.9, 6.5, and 3.2 years, respectively). Accordingly, for both decedents with and without diabetes, an initial increase in HbA1c was followed by an accelerating terminal decline starting 5-6 years before death. Conclusions and implications: The time-varying association between HbA1c and mortality mapped to the terminal trajectory in HbA1c. High and low HbA1c may have different clinical relationships with mortality. The HbA1c paradox may be partially explained by reverse causation, namely, early manifestation of death.

Multi-copy expression of a protease-resistant xylanase with high xylan degradation ability and its application in broilers fed wheat-based diets.

The acidic thermostable xylanase (AT-xynA) has great potential in the feed industry, but its low activity is not conductive to large-scale production, and its application in poultry diets still needs to be further evaluated. In Experiment1, AT-xynA activity increased 3.10 times by constructing multi-copy strains, and the highest activity reached 10,018.29 ± 91.18 U/mL. AT-xynA showed protease resistance, high specificity for xylan substrates, xylobiose and xylotriose were the main hydrolysates. In Experiment2, 192 broilers were assigned into 3 treatments including a wheat-based diet, and the diets supplemented with AT-xynA during the entire period (XY-42) or exclusively during the early stage (XY-21). AT-xynA improved growth performance, while the performance of XY-21 and XY-42 was identical. To further clarify the mechanism underlying the particular effectiveness of AT-xynA during the early stage, 128 broilers were allotted into 2 treatments including a wheat-based diet and the diet supplemented with AT-xynA for 42 d in Experiment3. AT-xynA improved intestinal digestive function and microbiota composition, the benefits were stronger in younger broilers than older ones. Overall, the activity of AT-xynA exhibiting protease resistance and high xylan degradation ability increased by constructing multi-copy strains, and AT-xynA was particularly effective in improving broiler performance during the early stage.

Ten-eleven translocation 1 mediating DNA demethylation regulates the proliferation of chicken primordial germ cells through the activation of Wnt4/ß-catenin signaling pathway.

OBJECTIVE: The objective of this study was to investigate the regulation relationship of Teneleven translocation 1 (Tet1) in DNA demethylation and the proliferation of primordial germ cells (PGCs) in chickens. METHODS: siRNA targeting Tet1 was used to transiently knockdown the expression of Tet1 in chicken PGCs, and the genomic DNA methylation status was measured. The proliferation of chicken PGCs was detected by flow cytometry analysis and cell counting kit-8 assay when activation or inhibition of Wnt4/ß-catenin signaling pathway. And the level of DNA methylation and hisotne methylation was also tested. RESULTS: Results revealed that knockdown of Tet1 inhibited the proliferation of chicken PGCs and downregulated the mRNA expression of Cyclin D1 and cyclin-dependent kinase 6 (CDK6), as well as pluripotency-associated genes (Nanog, PouV, and Sox2). Flow cytometry analysis confirmed that the population of PGCs in Tet1 knockdown group displayed a significant decrease in the proportion of S and G2 phase cells, which meant that there were less PGCs entered the mitosis process than that of control. Furthermore, Tet1 knockdown delayed the entrance to G1/S phase and this inhibition was rescued by treated with BIO. Consistent with these findings, Wnt/ß-catenin signaling was inactivated in Tet1 knockdown PGCs, leading to aberrant proliferation. Further analysis showed that the methylation of the whole genome increased significantly after Tet1 downregulation, while hydroxymethylation obviously declined. Meanwhile, the level of H3K27me3 was upregulated and H3K9me2 was downregulated in Tet1 knockdown PGCs, which was achieved by regulating Wnt/ß-catenin signaling pathway. CONCLUSION: These results suggested that the self-renewal of chicken PGCs and the maintenance of their characteristics were regulated by Tet1 mediating DNA demethylation through the activation of Wnt4/ß-catenin signaling pathway.