[Eucommia ulmoides Oliv polysaccharide reduces the injury of IL-1ß-induced chondrocyte by inhibiting NF-κB pathway].

OBJECTIVE: To investigate the effects of Eucommia ulmoides Oliv polysaccharide on the injury of interleukin-1ß(IL-1ß)-induced chondrocyte and its possible mechanism. METHODS: ATDC5 was treated with 10 µg/ml IL-1ß to establish osteoarthritis chondrocyte inflammation model, mouse chondrocyte ATDC5 were cultured in vitro and randomly divided into blank group, model group, model+Eucommia ulmoides Oliv polysaccharide low concentration group, model+Eucommia ulmoides Oliv polysaccharide medium concentration group and model+Eucommia ulmoides Oliv polysaccharide high concentration group. The cells in the blank group were cultured with conventional medium;the cells in the model group cells were cultured with a medium containing 10 ?g/ml IL-1ß, and the cells in the model+Eucommia ulmoides Oliv polysaccharide low concentration group, model+Eucommia ulmoides Oliv polysaccharide medium concentration group and model+Eucommia ulmoides Oliv polysaccharide high concentration group were co-cultured with medium containing 100, 200, 400 µg/ml Eucommia ulmoides Oliv polysaccharide and 10 µg/ml IL-1ß. After the cells of each group were cultured for 24 h, 48 h and 72 h, CCK-8 method was used to detect cell viability. After the cells of each group were cultured for 48 h, flow cytometry and DAPI staining were used to detect cell apoptosis;ELISA method was used to detect the expression of TNF-α, NO, IFN-γ and IL-6 in cells; DCFH-DA method was used to detect the content of ROS in cells;Western blot was used to detect the protein expression of TIMP-1, MMP-13 and NF-κB signaling pathway-related P65 and p-P65;Immunofluorescence staining was used to observe the localization of NF-κB P65 cells. RESULTS: Compared with the blank group, the ATDC5 cell viability and the protein expression of TIMP-1 in the model group reduced (P<0.05), while apoptosis rate, the levels of TNF-α, NO, IFN-γ and IL-6, the content of ROS, the protein expression of MMP-13 and p-P65, and the number of P65+ in the nucleus increased(P<0.05). Compared with the model group, the ATDC5 cell viability and the protein expression of TIMP-1 in the model+Eucommia ulmoides Oliv polysaccharide low concentration group, model+Eucommia ulmoides Oliv polysaccharide medium concentration group and model+Eucommia ulmoides Oliv polysaccharide high concentration group increased (P<0.05), while apoptosis rate, the levels of TNF-α, NO, IFN-γ and IL-6, the content of ROS, the protein expression of MMP-13 and p-P65, and the number of P65+ in the nucleus reduced (P<0.05). CONCLUSION: The results showed that Eucommia ulmoides Oliv polysaccharide could promote proliferation of IL-1ß-induced chondrocyte ATDC5 and inhibit its apoptosis, inflammatory response and matrix degradation. Its mechanism may be related to the inhibition of the activation of NF-κB pathway.

NGF-Induced Nav1.7 Upregulation Contributes to Chronic Post-surgical Pain by Activating SGK1-Dependent Nedd4-2 Phosphorylation.

At present, chronic post-surgical pain (CPSP) is difficult to prevent and cure clinically because of our lack of understanding of its mechanisms. Surgical injury induces the upregulation of voltage-gated sodium channel Nav1.7 in dorsal root ganglion (DRG) neurons, suggesting that Nav1.7 is involved in the development of CPSP. However, the mechanism leading to persistent dysregulation of Nav1.7 is largely unknown. Given that nerve growth factor (NGF) induces a long-term increase in the neuronal hyperexcitability after injury, we hypothesized that NGF might cause the long-term dysregulation of Nav1.7. In this study, we aimed to investigate whether Nav1.7 regulation by NGF is involved in CPSP and thus contributes to the specific mechanisms involved in the development of CPSP. Using conditional nociceptor-specific Nav1.7 knockout mice, we confirmed the involvement of Nav1.7 in NGF-induced pain and identified its role in the maintenance of pain behavior during long-term observations (up to 14 days). Using western blot analyses and immunostaining, we showed that NGF could trigger the upregulation of Nav1.7 expression and thus support the development of CPSP in rats. Using pharmacological approaches, we showed that the increase of Nav1.7 might be partly regulated by an NGF/TrkA-SGK1-Nedd4-2-mediated pathway. Furthermore, reversing the upregulation of Nav1.7 in DRG could alleviate spinal sensitization. Our results suggest that the maintained upregulation of Nav1.7 triggered by NGF contributes to the development of CPSP. Attenuating the dysregulation of Nav1.7 in peripheral nociceptors may be a strategy to prevent the transition from acute post-surgical pain to CPSP.

Preparation of well-distributed titania nanopillar arrays on Ti6Al4V surface by induction heating for enhancing osteogenic differentiation of stem cells.

Great effort has recently been devoted to the preparation of nanoscale surfaces on titanium-based implants to achieve clinically fast osteoinduction and osseointegration, which relies on the unique characteristics of the nanostructure. In this work, we used induction heating treatment (IHT) as a rapid oxidation method to fabricate a porous nanoscale oxide layer on the Ti6Al4V surface for better medical application. Well-distributed vertical nanopillars were yielded by IHT for 20-35 s on the alloy surface. The composition of the oxides contained rutile/anatase TiO2 and a small amount of Al2O3 between the TiO2 grain boundaries (GBs). This technology resulted in a reduction and subsequent increase of surface roughness of 26-32 nm when upregulating the heating time, followed by the successive enhancement of the thickness, wettability and adhesion strength of the oxidation layer to the matrix. The surface hardness also distinctly rose to 554 HV in the IHT-35 s group compared with the 350 HV of bare Ti6Al4V. The massive small-angle GBs in the bare alloy promoted the formation of nanosized oxide crystallites. The grain refinement and deformation texture reduction further improved the mechanical properties of the matrix after IHT. Moreover, in vitro experiments on a mesenchymal stem cell (BMSC) culture derived from human bone marrow for 1-7 days indicated that the nanoscale layers did not cause cytotoxicity, and facilitated cell differentiation in osteoblasts by enhancing the gene and osteogenesis-related protein expressions after 1-3 weeks of culturing. The increase of the IHT time slightly advanced the BMSC proliferation and differentiation, especially during long-term culture. Our findings provide strong evidence that IHT oxidation technology is a novel nanosurface modification technology, which is potentially promising for further clinical development.