Wavelength-tunable broadband lasers based on nanomaterials.

Nanomaterials are widely used in the fields of sensors, optoelectronics, biophotonics and ultrafast photonics due to their excellent mechanical, thermal, optical, electrical and magnetic properties. Particularly, owing to their nonlinear optical properties, fast response time and broadband operation, nanomaterials are ideal saturable absorption materials in ultrafast photonics, which contribute to the improvement of laser performance. Therefore, nanomaterials are of great importance to applications in wavelength-tunable broadband pulsed lasers. Herein, we review the integration and applications of nanomaterials in wavelength-tunable broadband ultrafast photonics. Firstly, the two integration methods, which are direct coupling and evanescent field coupling, and their characteristics are introduced. Secondly, the applications of nanomaterials in wavelength-tunable broadband lasers are summarized. Finally, the development of nanomaterials and broadband tunable lasers is reviewed and discussed.

Commensal Staphylococcus epidermidis Defends against Staphylococcus aureus through SaeRS Two-Component System.

Staphylococcus aureus is a high-virulent Gram-positive pathogen that is responsible for a serious of diseases. The emergence of antibiotic-resistant S. aureus poses a significant challenge in terms of treatment. The recent research on the human microbiome suggested that the application of commensal bacteria is a new strategy for combating pathogenic infections. Staphylococcus epidermidis, one of the most abundant species in the nasal microbiome, is able to inhibit the colonization of S. aureus. However, during bacterial competition, S. aureus undergoes evolutionary changes to adapt to the diverse environment. Our study has demonstrated that the nasal colonized S. epidermidis possesses the ability to inhibit the hemolytic activity of S. aureus. Moreover, we deciphered another layer of mechanism to inhibit S. aureus colonization by S. epidermidis. The active component present in the cell-free culture of S. epidermidis was found to significantly reduce the hemolytic activity of S. aureus in SaeRS- and Agr-dependent manner. Specifically, the hemolytic inhibition on the S. aureus Agr-I type by S. epidermidis is primarily dependent on the SaeRS two-component system. The active component is characterized as a small molecule that is heat sensitive and protease resistant. Critically, S. epidermidis significantly inhibit the virulence of S. aureus in a mouse skin abscess model, suggesting that the active compound could potentially be used as a therapeutic agent for managing S. aureus infections.

Ferulic acid inhibits bovine endometrial epithelial cells against LPS-induced inflammation via suppressing NK-κB and MAPK pathway.

Endometritis is one of the most common reproductive diseases caused by bacterial infection in the cow. Ferulic acid is a major effective component extracted from Ligusticum wallichii. Ferulic acid displays pharmacological effects such as anti-inflammation and antioxidation. The aim of the present study was to investigate the protective effects of ferulic acid on inflammation induced by lipopolysaccharide (LPS) in bovine endometrial epithelial cells (BEECs). BEECs were pretreated with ferulic acid followed by LPS treatment. QRT-PCR analysis showed the mRNA expression of LPS-induced proinflammatory cytokines (IL1B, IL6, TNFA, and IL8) was decreased with ferulic acid pretreatment. Western blot analysis showed that ferulic acid inhibited the degradation of IκB and phosphorylation of NF-κB p65. Ferulic acid suppressed the phosphorylation of MAPKs, including p38 and JNK. All of these results indicated that ferulic acid may be considered as a potential anti-inflammatory drug for curing endometritis.

A Novel Biological Role of α-Mangostin via TAK1-NF-κB Pathway against Inflammatory.

The oxysterone α-mangostin is isolated from mangosteen husks and is widely used in the treatment of abdominal pain, diarrhea, and dysentery. In this study, we established a lipopolysaccharide (LPS)-induced inflammatory model of rat intestinal epithelial cells (IEC-6 cells), at the same time we used differently concentration α-mangostin to detect its anti-inflammatory activity. We applied doses of α-mangostin (2.5, 5, and 10 µM) and detected apoptosis by flow cytometry, and the Griess reagent and the enzyme-linked immunosorbent assay (ELISA) method detected inflammatory factors such as nitric oxide (NO), prostaglandin (PG) E2, interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α. We also used quantitative real-time PCR (Q-PCR) to examine inflammatory factors and western blotting to examine the activation of transforming growth factor-activated kinase (TAK)-1-nuclear factor (NF)-κB signaling pathway-related proteins. Finally, we used laser confocal microscopy to detect the effect of the 10 µM α-mangostin on the nuclear import of NF-κB-p65. The results showed that α-mangostin treatment significantly reduced the apoptosis of LPS-stimulated IEC-6 cells, the production of inflammatory factors, the activation of TAK1-NF-κB signaling pathway-related proteins, and the entry of p65 into the nucleus. In conclusion, α-mangostin exerts its anti-inflammatory effects by inhibiting the activation of TAK1-NF-κB and it may be a potential choice for the treatment of inflammation diseases.

Magnolol pretreatment attenuates heat stress-induced IEC-6 cell injury.

OBJECTIVE: Heat stress (HS) is an important environmental stressor that adversely influences livestock during the summer. The aim of this study was to investigate whether magnolol protects against HS-induced intestinal epithelial cell injury. MATERIALS AND METHODS: An intestinal epithelial cell line (IEC-6) was subjected to HS at 42 °C, with and without magnolol pretreatment. Cell injury was detected by monitoring lactate dehydrogenase (LDH) release. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was used to assess cell proliferation and viability, including identifying effective concentrations of magnolol. Flow cytometry confirmed G1-phase cell-cycle arrest and its alleviation by magnolol. Active DNA synthesis was measured by incorporation of nucleic acid 5-ethynyl-2'-deoxyuridine (EdU). G1-phase cell-cycle-related gene expression was assessed by real-time reverse transcription polymerase chain reaction (RT-PCR) and levels of G1-phase-related proteins by Western blotting. RESULTS: HS induced IEC-6 cell injury and decreased cell viability, as demonstrated by data from LDH and MTS assays, respectively. Based on a number of criteria, IEC-6 cells subjected to HS were arrested in the G1 phase of the cell cycle. Magnolol pretreatment decreased HS-induced cell injury through relief of this cell-cycle arrest. CONCLUSIONS: Magnolol pretreatment attenuates HS-induced injury in IEC-6 cells. Magnolol is potentially promising as a protective strategy for HS in livestock.

Punicalagin induces Nrf2 translocation and HO-1 expression via PI3K/Akt, protecting rat intestinal epithelial cells from oxidative stress.

PURPOSE: Oxidative stress plays a central role in heat stress-induced gastrointestinal injury. Punicalagin (PUN), a major polyphenol abundant in pomegranate fruit, husk and juice, exhibits antioxidative effects. In this study we used a heat stress model to investigate the intestinal protection effect of PUN and the underlying mechanisms. MATERIALS AND METHODS: IEC-6 cells were pretreated with PUN for 6 h and exposed to 42 °C for 6 h. Intracellular reactive oxygen species levels, malondialdehyde, nitrogen oxide, and superoxide dismutase activity were measured. IEC-6 cells were treated with PUN at different times and doses, the protein levels of haeme oxygenase-1 (HO-1) were evaluated. The nuclear translocation of the transcription factor NF-erythroid 2-related factor (Nrf2) and the phosphorylation level of PI3K/Akt were also investigated. RESULTS: PUN significantly decreased the heat stress-induced cell death and apoptosis. Heat stress increased reactive oxygen species, malondialdehyde and nitrogen oxide production, while it decreased superoxide dismutase activity. These effects were markedly inversed when the cells were pretreated with PUN. Furthermore, PUN treatment induced the expression of HO-1 and increased Nrf2 nuclear translocation in a time- and dose-dependent manner. The Nrf2-related cytoprotective effects of PUN were via the PI3K/Akt signalling pathway, as LY294002, a specific PI3K/Akt inhibitor, suppressed the PUN-induced nuclear translocation of Nrf2, the HO-1 up-regulation and the protective effect of PUN against oxidative stress. CONCLUSIONS: PUN protects IEC-6 cells against oxidative stress by up-regulating the expression of HO-1 via a mechanism that involves PI3K/Akt activation and Nrf2 translocation.

The Anti-Apoptotic Role of Berberine in Preimplantation Embryo In Vitro Development through Regulation of miRNA-21.

Traditional Chinese medicinal herbs containing berberine have been historically used to prevent miscarriage. Here, we investigated whether the anti-apoptotic effects of berberine on pre-implantation embryonic development are regulated by miRNA-21. Mouse pronuclear embryos were cultured in medium with or without berberine, and some were then microinjected with a miRNA-21 inhibitor. The in vitro developmental rates of 2- and 4-cell embryos and blastocysts, blastocyst cell numbers, apoptotic rates, and apoptotic cell numbers were measured in each group. Furthermore, we examined the transcription levels of miRNA-21 and its target genes (caspase-3, PTEN, and Bcl-2) and their translation levels. Comparisons were made with in vivo-developed and untreated embryos. We found that berberine significantly increased the developmental rates and cell numbers of mouse blastocysts and decreased apoptotic cell rates in vitro. Berberine also significantly increased miRNA-21 and Bcl-2 transcription levels and significantly decreased caspase-3 and PTEN transcription levels. In embryos treated with a miRNA-21 inhibitor, the results followed the opposite trend; PTEN and caspase-3 transcription levels increased significantly, while the transcription level of Bcl-2 decreased significantly. Additionally, berberine treatment significantly increased the Bcl-2 protein level and significantly decreased the caspase-3 and PTEN protein levels in blastocysts, but there were no significant differences observed in the levels of these proteins in 2- and 4-cell embryos. This study revealed that miRNA-21 is important for pre-implantation embryonic development, especially blastocyst development in vitro. Berberine elevates miRNA-21 expression, decreases PTEN and caspase-3 levels, increases Bcl-2 levels, and exerts anti-apoptotic and pro-growth effects.

Polyphenol extracts from Punica granatum and Terminalia chebula are anti-inflammatory and increase the survival rate of chickens challenged with Escherichia coli.

Avian pathogenic Escherichia coli (APEC) causes inflammation in multiple organs of chickens called avian colibacillosis, and results in serious economic loss to the chicken industry. Polyphenolic compounds possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases. In this study, the curative effect and mechanism of action of the polyphenolic extracts from Punica granatum L. and Terminalia chebula Retz. in chickens challenged with APEC were studied. Specific-pathogen-free white Leghorn chickens (males, 21-d old) were challenged with APEC and then given oral administration of extracts of P. granatum and T. chebula. The extracts decreased the morbidity and inflammation induced by APEC. Data from quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay showed that the extracts of P. granatum and T. chebula polyphenols (GCP) reversed the over-expression genes of the Toll-like receptor (TLR) 2, 4, and 5, down-regulated the activation of nuclear factor-kappa B signal transduction pathways, and inhibited the production of pro-inflammatory cytokines. Naturally occurring GCP may be a potential alternative medicine for the prevention or treatment of avian colibacillosis.

Microarray analysis of intestinal immune-related gene expression in heat-stressed rats.

PURPOSE: This study aimed to investigate immune-related gene expression in rat small intestine after heat stress. MATERIALS AND METHODS: Twelve Sprague Dawley (SD) rats were randomly divided into control and heat-stressed groups. Rats in both groups were housed at 25 °C with 60% relative humidity. The heat-stressed group was subjected to 40 °C for 2 h/day for 3 days. After heat stress, the mRNA expression profile of small intestine epithelial tissue was evaluated by microarray analysis. RESULTS: A total of 23 genes related to immune responses were significantly altered, of which 12 genes were up-regulated and 11 genes were down-regulated. CONCLUSIONS: Microarray analysis demonstrated the JAK-STAT pathway had a potentially important role in the regulation of inflammation in the small intestine, and changes in antigen presentation might reduce intestinal immune responses after heat stress.

The regulatory role of icariin on apoptosis in mouse preimplantation embryos with reduced microRNA-21.

We constructed a model of apoptosis in mouse preimplantation embryos and investigated the effect of the flavonol icariin on embryonic development in vitro in embryos with reduced microRNA-21 (miR-21). The model was generated by microinjecting an miR-21 inhibitor into the cytoplasm of mouse pronuclear embryos, which were cultured in vitro using modified CZB (mCZB) basal medium (model group), or using mCZB medium with 0.6 µg/mL icariin as an experimental group (model-Ica). These were compared with embryos collected in vivo (vivo group) or not microinjected (control group). Developmental rates in vitro of two- and four-cell embryos and blastocysts were observed, and Hoechst 33342 and terminal deoxynucleotidyl transferase dUTP nick end labeling staining were used to count blastocyst cell numbers and apoptotic cell numbers and percentages. The transcriptional levels of miR-21, the apoptotic genes caspase 3 and phosphatase and tensin homolog deleted on chromosome ten (PTEN), and the antiapoptotic gene Bcl-2 were detected by quantitative polymerase chain reaction (qPCR). Western immunoblotting was used to detect the protein levels of caspase 3, PTEN, and Bcl-2. Compared with the model group, icariin treatment significantly improved blastocyst development in vitro (58.43 ± 7.53% vs. 37.85 ± 6.47%; P < 0.01), whereas it was not significantly different to the control group (60.34 ± 9.86%). Icariin treatment significantly increased the blastocyst cell numbers (47.02 ± 4.93 vs. 37.70 ± 5.80; P < 0.01), and reduced the rates of apoptosis (5.51 ± 2.35% vs. 10.11 ± 4.21%; P < 0.01), whereas the blastocyst cell numbers and apoptotic rates revealed no significant differences between the vivo (46.06 ± 6.50, 5.95 ± 2.56%) and control groups (45.77 ± 4.09, 6.18 ± 2.41%). Icariin treatment significantly improved miR-21 expression in all embryo stages, reduced the transcriptional levels of caspase 3 and PTEN, and increased the levels of Bcl-2. The protein expression levels of caspase 3 and PTEN were decreased in blastocysts and the level of Bcl-2 was increased (P < 0.01). These had no significant differences with the vivo and control groups, and the protein levels revealed no significant differences between two- and four-cell embryos. Thus, miR-21 was necessary for preimplantation embryonic development, and embryo quality was closely associated with the apoptosis-related protein expression levels regulated by miR-21. Icariin upregulated miR-21 expression and reduced apoptosis in embryos with reduced miR-21. It also improved embryonic developmental quality in vitro, indicating an important regulatory role for miR-21 in blastocyst development in vitro.