ABSTRACT
Osteoclasts are over-activated as we age, which results in bone loss. Src deficiency in mice leads to severe osteopetrosis due to a functional defect in osteoclasts, indicating that Src function is essential in osteoclasts. G-protein-coupled receptors (GPCRs) are the targets for â¼35% of approved drugs but it is still unclear how GPCRs regulate Src kinase activity. Here, we reveal that GPR54 activation by its natural ligand Kisspeptin-10 (Kp-10) causes Dusp18 to dephosphorylate Src at Tyr 416. Mechanistically, Gpr54 recruits both active Src and the Dusp18 phosphatase at its proline/arginine-rich motif in its C terminus. We show that Kp-10 binding to Gpr54 leads to the up-regulation of Dusp18. Kiss1, Gpr54 and Dusp18 knockout mice all exhibit osteoclast hyperactivation and bone loss, and Kp-10 abrogated bone loss by suppressing osteoclast activity in vivo. Therefore, Kp-10/Gpr54 is a promising therapeutic target to abrogate bone resorption by Dusp18-mediated Src dephosphorylation.
Subject(s)
Bone Resorption , Osteoclasts , Animals , Mice , Osteoclasts/metabolism , Kisspeptins/genetics , Kisspeptins/metabolism , Receptors, G-Protein-Coupled/metabolism , src-Family Kinases/genetics , src-Family Kinases/metabolism , Mice, Knockout , Bone Resorption/genetics , Receptors, Kisspeptin-1ABSTRACT
This study was performed to extract and separate the volatiles with solid-phase microextraction (SPME), and was conducted to analyze volatile odor compounds qualitatively and quantitatively in the production of a strong aroma tallow by mild oxidation. A total of 51 odor compounds were detected in the tallow smelted under different conditions. It was found that the high proportion of aldehydes was an important feature of the aroma components in the oxidized melted tallow, such as 1-hexanal, heptanal, nonanal, octanal, benzaldehyde, etc. Through the determination of various indicators, sensory evaluation, and the gas chromatography-olfaction-mass spectrometry (GC-O-MS) analysis and, in combination with response surface methodology, the optimal process parameters for oxidative smelting of tallow were determined as follows: a reaction temperature of 149.61 °C, a reaction time of 31.68 min, and an airflow rate of 97.44 L/h. The accelerated oxidation test further verified the quality of the oxidized tallow.
Subject(s)
Odorants , Volatile Organic Compounds , Odorants/analysis , Volatile Organic Compounds/analysis , Smell , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methodsABSTRACT
BACKGROUND: Atherosclerosis is one of the main causes of coronary artery ostial lesions seen clinically. Secondary coronary artery ostial lesions are rare, and cases reported previously were associated with syphilitic vasculitis and aortic dissection. Here, we report three rare cases of secondary coronary ostial lesions. Due to their rareness, these lesions can easily be neglected, which may lead to misdiagnosis and missed diagnosis. CASE SUMMARY: We present three patients with acute myocardial infarction and unstable angina caused by secondary coronary artery ostial lesions. In Case 1, coronary angiography (CAG) revealed 90% stenosis of the left main coronary ostium. Chest contrast computed tomography (CT) suggested thymic carcinoma invading the left main coronary ostium. Coronary artery bypass grafting and tumor resection were performed. In Case 2, echocardiography revealed a sinus of Valsalva aneurysm (SVA)-like dilatation. CAG showed a right coronary sinus giant aneurysm and complete obstruction of the right coronary artery (RCA) ostium. Aortic contrast CT confirmed these findings. The Bentall procedure was performed. In Case 3, CT CAG identified an anomalous origin of the right coronary artery (AORCA) from the left sinus of Valsalva coursing between the aorta and pulmonary trunk, causing severe RCA ostium stenosis by compression. Surgical correction of the AORCA was performed. CONCLUSION: The cases reported here suggest that we should consider other causes of coronary ostial lesions other than atherosclerosis.
ABSTRACT
Polyacrylate emulsions were prepared by Pickering emulsion polymerization with multi-modified hectorite as a modifier. The proper wettability of modified hectorite and the stability of O/W emulsions prove that modified hectorite has good emulsification properties. The stability of polyacrylate latexes and the morphology of polymer latex particles were then investigated to explain the role of multi-modified hectorite in stabilizing polyacrylate latex. In addition, the improved mechanical properties and water resistance of the latex make it a potentially excellent coating. Multi-modified hectorite as an alternative modifier to conventional surfactants offers a potential application of nanosolid particles that meet the partial wetting conditions for water and oil as stabilizers for the production of latexes for coatings.
ABSTRACT
Transcriptional cyclin-dependent kinases regulate all phases of transcription. Cyclin-dependent kinase 9 (CDK9) has been implicated in the regulation of promoter-proximal pausing of RNA polymerase II and more recently in transcription termination. Study of the substrates of CDK9 has mostly been limited to in vitro approaches that lack a quantitative assessment of CDK9 activity. Here we analyzed the cellular phosphoproteome upon inhibition of CDK9 by combining analog-sensitive kinase technology with quantitative phosphoproteomics in Raji B-cells. Our analysis revealed the activity of CDK9 on 1102 phosphosites quantitatively, and we identified 120 potential cellular substrates. Furthermore, a substantial number of CDK9 substrates were described as splicing factors, highlighting the role of CDK9 in transcription-coupled splicing events. Based on comparison to in vitro data, our findings suggest that cellular context fundamentally impacts the activity of CDK9 and specific selection of its substrates.
ABSTRACT
Heterochromatin is a distinctive chromatin structure that is essential for chromosome segregation, genome stability and regulation of gene expression. H3K9 methylation (H3K9me), a hallmark of heterochromatin, is deposited by the Su(var)3-9 family of proteins; however, the mechanism by which H3K9 methyltransferases bind and methylate the nucleosome is poorly understood. In this work we determined the interaction of Clr4, the fission yeast H3K9 methyltransferase, with nucleosomes using nuclear magnetic resonance, biochemical and genetic assays. Our study shows that the Clr4 chromodomain binds the H3K9me3 tail and that both, the chromodomain and the disordered region connecting the chromodomain and the SET domain, bind the nucleosome core. We show that interaction of the disordered region with the nucleosome core is independent of H3K9me and contributes to H3K9me in vitro and in vivo. Moreover, we show that those interactions with the nucleosome core are contributing to de novo deposition of H3K9me and to establishment of heterochromatin.
Subject(s)
Cell Cycle Proteins/metabolism , DNA, Fungal/metabolism , Heterochromatin/metabolism , Histone Code , Histone-Lysine N-Methyltransferase/metabolism , Methyltransferases/metabolism , Nucleosomes/metabolism , Schizosaccharomyces pombe Proteins/metabolism , Schizosaccharomyces/genetics , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/genetics , Gene Deletion , Heterochromatin/ultrastructure , Histone-Lysine N-Methyltransferase/chemistry , Methyltransferases/chemistry , Methyltransferases/genetics , Models, Molecular , Mutagenesis, Insertional , Mutation, Missense , Nucleic Acid Conformation , Protein Binding , Protein Conformation , Protein Domains , Protein Interaction Mapping , RNA, Fungal/metabolism , Recombinant Fusion Proteins/metabolism , Schizosaccharomyces/growth & development , Schizosaccharomyces pombe Proteins/chemistry , Schizosaccharomyces pombe Proteins/geneticsABSTRACT
Fungal degradation of lignocellulosic biomass requires various (hemi-)cellulases and is an important part of the natural carbon cycle. Although induction of cellulases has been described for some saprobic filamentous fungi, the regulation of cellulase transcription is complex and many aspects are still poorly understood. Here, we identified and characterized the novel cellulase regulation factor NcCLR-4 in Neurospora crassa and its ortholog MtCLR-4 in Myceliophthora thermophila. Deletion of CLR-4 resulted in similarly defective cellulolytic enzyme production and activities. Transcriptome analyses of ΔNcclr-4/ΔMtclr-4 revealed the down-regulation of genes encoding (hemi-)cellulases and pivotal regulators (clr-1, clr-2 and xyr-1) and key genes in the cAMP signaling pathway such as adenylate cyclase Nccr-1. Intracellular cAMP levels were markedly lower in ΔNcclr-4/ΔMtclr-4 than in wild-type during cellulose utilization. In electrophoretic mobility shift (EMSA) and DNase I footprinting assays, NcCLR-4/MtCLR-4 can directly bound to the promoters of Nccr-1/Mtcr-1 (encoding adenylyl cyclase). EMSAs also demonstrated that NcCLR-4/MtCLR-4 could directly bound to clr-1 (encoding a key cellulase regulator), Mtclr-2 and Mtxyr-1 (encoding biomass deconstruction regulators). These findings about the novel cellulase expression regulators NcCLR-4 and MtCLR-4 enrich our understanding of how cellulose degradation is regulated and provide new targets for engineering fungi to deconstruct plant biomass in biorefineries.
Subject(s)
Cellulase/biosynthesis , Gene Expression Regulation, Fungal , Sordariales/enzymology , Transcription Factors/genetics , Transcription Factors/metabolism , Gene Deletion , Gene Expression Profiling , Sordariales/genetics , Transcription Factors/deficiencyABSTRACT
In this paper, a WSe2 film prepared by chemical vapor deposition (CVD) is transferred onto a tapered fiber, and a WSe2 saturable absorber (SA) is fabricated. In order to measure the third-order optical nonlinearity of the WSe2, the Z-scan technique is applied. The modulation depth of the WSe2 SA is measured as being 21.89%. Taking advantage of the remarkable nonlinear absorption characteristic of the WSe2 SA, a mode-locked erbium-doped fiber laser is demonstrated at 1557.4 nm with a bandwidth of 25.8 nm and signal to noise ratio of 96 dB. To the best of our knowledge, the pulse duration of 163.5 fs is confirmed to be the shortest compared with previous mode-locked fiber lasers based on transition-metal dichalcogenides SAs. These results indicate that WSe2 is a powerful competitor in the application of ultrashort pulse lasers.
ABSTRACT
Carotenoids are considered to be crucial elements in many fields and, furthermore, the significant factor in pepper leaves under low light and chilling temperature. However, little literature focused on the method to determinate and extract the contents of carotenoid compositions in pepper leaves. Therefore, a time-saving and highly sensitive reversed-phase high-performance liquid chromatography method for separation and quantification of 10 carotenoids was developed, and an optimized technological process for carotenoid composition extraction in pepper leaves was established for the first time. Our final method concluded that six xanthophylls eluted after about 9-26 min. In contrast, four carotenes showed higher retention times after nearly 28-40 min, which significantly shortened time and improved efficiency. Meanwhile, we suggested that 8 mL of 20% KOH-methanol solution should be added to perform saponification at 60 °C for 30 min. The ratio of solid-liquid was 1:8, and the ultrasound-assisted extraction time was 40 min.
Subject(s)
Capsicum/chemistry , Carotenoids/chemistry , Plant Extracts/chemistry , Chromatography, High Pressure Liquid , Chromatography, Reverse-Phase , Plant Leaves/chemistryABSTRACT
BACKGROUND: Lignocellulolytic fungal cells suffer endoplasmic reticulum (ER) stress during lignocellulase synthesis; however, an understanding of this integrated process on a genome-wide scale remains poor. Here, we undertook a systematic investigation of this process in Neurospora crassa (N. crassa) using transcriptomic analysis coupled with genetic screens. RESULTS: A set of 766 genes was identified as the ER stress response targets (ESRTs) in N. crassa under cellulose utilization conditions. Among these, the expression of 223 and 186 genes showed dependence on IRE-1 and HAC-1, respectively. A total of 527 available mutants for ESRT genes were screened, 249 of which exhibited ER stress susceptibility, including 100 genes with unknown function. Disruption of ire-1 or hac-1 in N. crassa did not affect transcriptional induction of lignocellulase genes by cellulose but severely affected secretion of the corresponding enzymes. A global investigation of transcription factors (TFs) discovered three novel regulators (RES-1, RES-2, RRG-2) involved in lignocellulase secretion. Production of lignocellulases in Δres-1 increased by more than 30% in comparison to wild type (WT), while secretion decreased by nearly 30% in strains Δres-2 and Δrrg-2. Transcriptional profiling of the three TF mutants suggests they are deeply involved in lignocellulase secretion and ER stress response. CONCLUSIONS: Here, we determined the transcriptional scope of the ER stress response during lignocellulase synthesis in the model cellulolytic fungus N. crassa. Through genome-wide mutant screening and analysis, dozens of novel genes were discovered to be involved in the process. The findings of this work will be useful for strain improvement to facilitate lignocellulase and biomass-based chemical production.
ABSTRACT
In the title compound, C(25)H(22)BrN(3)O(5)S, the central benzene ring makes dihedral angles of 4.41â (10), 67.09â (9) and 62.05â (10)°, respectively, with the pyrazolone, bromo-benzene and terminal phenyl rings. The dihedral angle between the pyrazolone and phenyl rings is 57.75â (11)°. In the crystal, two pairs of C-Hâ¯O hydrogen bonds link the mol-ecules into inversion dimers. A weak intra-molecular C-Hâ¯O hydrogen bonds is also observed.
ABSTRACT
In the title compound, C(15)H(13)NO(5), the two benzene rings make a dihedral angle of 3.98â (7)°. The crystal packing is stabilized by weak non-classical inter-molecular C-Hâ¯O inter-actions that link mol-ecules into centrosymmetric tetra-mers.