CtBP1 Overexpression in Keratinocytes Perturbs Skin Homeostasis

Carboxyl-terminal–binding protein-1 (CtBP1) is a transcriptional corepressor with multiple in vitro targets, but its in vivo functions are largely unknown. We generated keratinocyte-specific CtBP1 transgenic mice with a keratin-5 promoter (K5.CtBP1) to probe the pathological roles of CtBP1. At transgene expression levels comparable to endogenous CtBP1 in acute skin wounds, the K5.CtBP1 epidermis displayed hyperproliferation, loss of E-cadherin, and failed terminal differentiation. Known CtBP1 target genes associated with these processes, e.g., p21 Brca1, and E-cadherin, were downregulated in K5.CtBP1 skin. Surprisingly, K5.CtBP1 pups also exhibited a hair loss phenotype. We found that expression of the Distal-less 3 (Dlx3), a critical regulator of hair follicle differentiation and cycling, was decreased in K5.CtBP1 mice. Molecular studies revealed that CtBP1 directly suppressed Dlx3 transcription. Consistently, K5.CtBP1 mice displayed abnormal hair follicles with decreased expression of Dlx3 downstream targets Gata3 Hoxc13, and hair keratins. In summary, this CtBP1 transgenic model provides in vivo evidence for certain CtBP1 functions predicted from in vitro studies, reveals—to our knowledge—previously unreported functions and transcriptional activities of CtBP1 in the context of epithelial–mesenchymal interplay, and suggests that CtBP1 has a pathogenic role in hair follicle morphogenesis and differentiation

Polyacrylonitrile nanofibers coated with silver nanoparticles using a modified coaxial electrospinning process

Background: The objective of this investigation was to develop a new class of antibacterial material in the form of nanofibers coated with silver nanoparticles (AgNPs) using a modified coaxial electrospinning approach. Through manipulation of the distribution on the surface of nanofibers, the antibacterial effect of Ag can be improved substantially. Methods: Using polyacrylonitrile (PAN) as the filament-forming polymer matrix, an electrospinnable PAN solution was prepared as the core fluid. A silver nitrate (AgNO3) solution was exploited as sheath fluid to carry out the modified coaxial electrospinning process under varied sheath-to-core flow rate ratios. Results: Scanning electron microscopy and transmission electron microscopy demonstrated that the sheath AgNO3 solution can take a role in reducing the nanofibers’ diameters significantly, a sheath-to-core flow rate ratio of 0.1 and 0.2 resulting in PAN nanofibers with diameters of 380 ± 110 nm and 230 ± 70 nm respectively. AgNPs are well distributed on the surface of PAN nanofibers. The antibacterial experiments demonstrated that these nanofibers show strong antimicrobial activities against Bacillus subtilis Wb800, and Escherichia coli dh5α. Conclusion: Coaxial electrospinning with AgNO3 solution as sheath fluid not only facilitates the electrospinning process, providing nanofibers with reduced diameters, but also allows functionalization of the nanofibers through coating with functional ingredients, effectively ensuring that the active antibacterial component is on the surface of the material, which leads to enhanced activity. We report an example of the systematic design, preparation, and application of a novel type of antibacterial material coated with AgNPs via a modified coaxial electrospinning methodology

Chemical composition of the volatile oil of Chenopodium ambrosioides L. from Mianyang in Sichuan Province of China and its sub-chronic toxicity in mice

Purpose: To determine the chemical constituents of the volatile oil of Chenopodium ambrosioides L. from Mianyang in Sichuan Province of China, and assess the sub-chronic toxicity of the volatile oil in mice.Methods: The volatile chemical components were analyzed by gas chromatography-mass spectrometry (GC-MS). Sixty Kunming mice were divided into six groups of ten mice each. One group served as control (no treatment), two groups were orally administered ρ-cymene at doses of 3 and 7 mg/kg, respectively, for 27 days, while three groups received the volatile oil at doses of 10, 25 and 40 mg/kg, respectively, for the same duration. Sub-chronic toxicity in the mice was evaluated by observing their general behavior, measuring serum levels of aspartate transaminase (AST) and alanine transaminase (ALT), evaluating liver, heart, kidney and thymus indices, and assessing the histological morphology of the organs.Results: The volatile oil contained 14 chemical components, of which α-terpinene and ρ-cymene accounted for 32.89 and 24.25 %, respectively. The volatile oil caused significant (p < 0.05) increase in liver index, and serum AST and ALT levels, and also induced distinct morphological changes in mouse liver, heart and kidney.Conclusion: The main volatile components of the oil are α-terpinene and ρ-cymene. The volatile oil showed dose-dependent toxicity in mice, thus lending some support for the safe use of C. ambrosioides in traditional medicine. Keywords: Chenopodium ambrosioides, Volatile oil, Oral toxicity, AST and ALT, Histopathological change

Identifying the determinants and spatial nexus of provincial carbon intensity in China: A dynamic spatial panel approach

Is emission intensity of carbon dioxide (CO2) spatially correlated? What determines the CO2 intensity at a provincial level? More importantly, what climate and economic policy decisions should the China’s central and local governments make to reduce the CO2 intensity and prevent the environmental pollution given that China has been the largest emitter of CO2? We aim to address these questions in this study by applying a dynamic spatial system-GMM (generalized method of moment) technique. Our analysis suggests that provinces are influenced by their neighbours. In addition, CO2 intensities are relatively higher in the western and middle areas, and that the spatial agglomeration effect of the provincial CO2 intensity is obvious. Our analysis also shows that CO2 intensity is nonlinearly related to GDP (gross domestic product), positively associated with secondary-sector share and FDI (foreign direct investment), and negatively associated with population size. Important policy implications are drawn on reducing carbon intensity