Sodium Selenite Enhances Antibiotics Sensitivity of Pseudomonas aeruginosa and Deceases Its Pathogenicity by Inducing Oxidative Stress and Inhibiting Quorum Sensing System.

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen, is commonly found in clinical settings and immuno-compromised patients. It is difficult to be eradicated due to its strong antibiotic resistance, and novel inactivation strategies have yet to be developed. Selenium is an essential microelement for humans and has been widely used in dietary supplement and chemoprevention therapy. In this study, the physiological and biochemical effects of sodium selenite on P. aeruginosa PAO1 were investigated. The results showed that 0~5 mM sodium selenite did not impact the growth of PAO1, but increased the lethality rate of PAO1 with antibiotics or H2O2 treatment and the antibiotics susceptibility both in planktonic and biofilm states. In addition, sodium selenite significantly reduced the expression of quorum sensing genes and inhibited various virulence factors of this bacterium, including pyocyanin production, bacterial motilities, and the type III secretion system. Further investigation found that the content of ROS in cells was significantly increased and the expression levels of most genes involved in oxidative stress were up-regulated, which indicated that sodium selenite induced oxidative stress. The RNA-seq result confirmed the phenotypes of virulence attenuation and the expression of quorum sensing and antioxidant-related genes. The assays of Chinese cabbage and Drosophila melanogaster infection models showed that the combination of sodium selenite and antibiotics significantly alleviated the infection of PAO1. In summary, the results revealed that sodium selenite induced oxidative stress and inhibited the quorum sensing system of P. aeruginosa, which in turn enhanced the antibiotic susceptibility and decreased the pathogenicity of this bacterium. These findings suggest that sodium selenite may be used as an effective strategy for adjunct treatment of the infections caused by P. aeruginosa.

Chi-miR-30b-5p inhibits dermal papilla cells proliferation by targeting CaMKIIδ gene in cashmere goat.

BACKGROUND: During goat embryonic morphogenesis and postnatal initiation of hair follicle (HF) regeneration, dermal papilla (DP) cells play a vital role in hair formation. Growing evidence shows that microRNAs (miRNAs) participate in HF development and DP cell proliferation. However, the molecular mechanisms have not been thoroughly investigated. RESULT: In this study, we utilized miRNA sequencing (miRNA-Seq) to identify differentially expressed miRNAs at different HF cycling stages (anagen and telogen). MiRNA-Seq has identified 411 annotated miRNAs and 130 novel miRNAs in which 29 miRNAs were up-regulated and 32 miRNAs were down-regulated in the anagen phase compared to the telogen phase. Target gene prediction and functional enrichment analysis indicated some major biological pathways related to hair cycling, such as Wnt signaling pathways, ECM-receptor interaction, VEGF signaling pathway, biosynthesis of amino acids, metabolic pathways, ribosome and oxidative phosphorylation. Also, we explored the function of chi-miR-30b-5p in regulating hair growth cycle. Similar to the HF cycling, DP cells were isolated from skin and used to investigate miRNA functions. The MTT and EdU assays showed that the viability and proliferation of DP cells were inhibited or promoted after the transfection of chi-miR-30b-5p mimic or inhibitor, respectively. Bioinformatics analysis revealed CaMKIIδ as a candidate target gene of chi-miR-30b-5p, and the dual-luciferase and western blot assay demonstrated that chi-miR-30b-5p bound to the 3'UTR of CaMKIIδ and further inhibited its translation. CONCLUSION: Chi-miR-30b-5p was found to be highly expressed in the telogen than that in the anagen phase and could inhibit the proliferation of DP cells by targeting CaMKIIδ. Our study provides new information on the regulatory functions of miRNAs during HF development.

Ferulic Acid Improves Depressive-Like Behavior in Prenatally-Stressed Offspring Rats via Anti-Inflammatory Activity and HPA Axis.

Prenatal stress (PS) can increase the risk of nervous, endocrine and metabolic diseases, and immune dysfunction. Ferulic acid (FA) is a dietary phenolic acid that has pharmacological properties, including potent anti-inflammatory action. We used male, prenatally-stressed offspring rats to investigate the anti-depressive-like effects and possible anti-inflammatory mechanism of FA. We determined the animal behaviors, and the mRNA expression and concentration of inflammatory cytokines, and HPA axis. In addition, we assessed the modulation of hippocampal nuclear factor-κB (NF-κB) activation, neuronal nitric oxide synthase (nNOS) and glucocorticoid receptors (GR) expression via western blotting and immunohistochemistry. Administration of FA (12.5, 25, and 50 mg/kg/day, i.g.) for 28 days markedly increased sucrose intake, and decreased immobility time and total number of crossings, center crossings, rearing, and grooming in the male PS offspring. FA significantly reduced IL-6, IL-1ß, and TNF-α concentration and increased IL-10 concentration in male, prenatally-stressed offspring, stimulated by the NF-κB pathway. In addition, FA inhibited interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α), and increased interleukin-10 (IL-10) mRNA and protein expression. Furthermore, FA markedly decreased the serum adrenocorticotropin (ACTH) and corticosterone concentration by the increase of GR protein expression. Taken together, this study revealed that FA has anti-depressive-like effects in male, prenatally-stressed offspring, partially due to its anti-inflammatory activity and hypothalamic-pituitary-adrenal (HPA) axis.