Inhibition of NF-kB 1 (NF-kBp50) by RNA interference in chicken macrophage HD11 cell line challenged with Salmonellaenteritidis

The NF-kB pathway plays an important role in regulating the immunity response in animals. In this study, small interfering RNAs (siRNA) were used to specifically inhibit NF-kB 1 expression and to elucidate the role of NF-kB in the signal transduction pathway of the Salmonella challenge in the chicken HD11 cell line. The cells were transfected with either NF-kB 1 siRNA, glyceraldehyde 3-phosphate dehydrogenase siRNA (positive control) or the negative control siRNA for 24 h, followed by Salmonella enteritidis (SE) challenge or non-challenge for 1 h and 4 h. Eight candidate genes related to the signal pathway of SE challenge were selected to examine the effect of NF-kB 1 inhibition on their expressions by mRNA quantification. The results showed that, with a 36% inhibition of NF-kB 1 expression, gene expression of both Toll-like receptor (TLR) 4 and interleukin (IL)-6 was consistently and significantly increased at both 1 h and 4 h following SE challenge, whereas the gene expression of MyD88 and IL-1β was increased at 1 h and 4 h, respectively. These findings suggest a likely inhibitory regulation by NF-kB 1, and could lay the foundation for studying the gene network of the innate immune response of SE infection in chickens

Fabrication and Characterization of Polyphosphazene/Calcium Phosphate Scaffolds Containing Chitosan Microspheres for Sustained Release of Bone Morphogenetic Protein 2 in Bone Tissue Engineering

Bone morphogenetic protein 2 has a major role in promoting bone regeneration in tissue engineering scaffolds. Growth factor release rate is a remaining crucial problem in these systems. The aim of this study was to fabricate and characterize a novel calcium phosphate/polyphosphazenes porous scaffold for the sustained release of bone morphogenetic protein 2 in bone tissue engineering. Polyphosphazenes were substituted with 2-dimethylaminoethanol and evaluated by GPC, NMR, and in vitro degradation. Calcium phosphate porous samples were prepared from hydroxyapatite nanoparticles and naphthalene using the sintering method at 1250 degrees C before being composited with poly(dimethylaminoethanol)phosphazenes containing chitosan microspheres loaded with bone morphogenetic protein 2. The characteristics and biodegradability of the product were evaluated by SEM, XRD, and in vitro degradation. Moreover, the release rate and mechanical properties of the scaffolds were investigated. The release behavior was found to be sustained since the scaffolds had been fabricated from polyphosphazenes with a low degradation rate. The release rates of the scaffolds were observed to increase with increasing chitosan microspheres content from 10 to 30. The bioactivity of the scaffolds depended on the release rate of growth factor while bone morphogenetic protein 2 was able to induce an osteoblast proliferation. The results of cell adhesion and cell viability tests showed that scaffolds displayed a non-toxic behavior and western blot analyses confirmed that the scaffolds loaded with growth factor increased the osteogenic differentiation potential of cells when compared with scaffolds alone. These results demonstrate that these scaffolds can be successfully utilized in bone tissue engineering