Objective:To investigate the effects of exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) during osteogenic differentiation on the polarization of Raw264.7 macrophages and to elucidate the underlying mechanisms.Methods:PBS, uninduced BMSCs conditioned medium (CM), and osteogenic induction BMSCs CM for 7 d, 14 d, and 21 d were respectively added to Raw264.7 macrophages. After 48 h of treatment, Western blotting was used to detect and compare the expression of M1 markers of macrophages [inducible nitric oxide synthase (iNOS) and CD86] and M2 markers of macrophages [arginase-1 (ARG-1) and CD163] in each group. In addition, Raw264.7 macrophages were divided into three groups: the PBS group (only PBS added), the BMSCs-exo group (exosomes derived from uninduced BMSCs were added), and 7D-BMSCs-exo (exosomes derived from BMSCs were added after 7 days of osteogenic induction). The absorbance values of Raw264.7 cells in each group at 24 h, 48 h and 72 h were detected by an enzyme-linked immunosorbent assay (ELISA) reader. Western blotting was performed to assess changes of M1 or M2 marker proteins in Raw264.7 macrophages treated by exosome. The supernatants of the three groups of Raw264.7 macrophages were then co-cultured with BMSCs. Alizarin Red staining was used to quantify the formation of mineralized nodules, and alkaline phosphatase (ALP) staining was used to evaluate the osteogenic activity, and the expression levels of osteogenesis-related proteins Runx2, ALP, osteopontin (OPN), and osteocalcin (OCN) were detected. The migration ability of endothelial progenitor cells (EPCs) was detected by scratch assay for migration distance, and the angiogenesis ability was detected by in vitro tube formation assay for the number of vascular rings formed. The expressions of vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF) were detected by Western blot. The activation of the MAPK signaling pathway was evaluated by measuring phosphorylated and total P38 and ERK1/2 levels.Results:Western blot analysis showed that CM from BMSCs after 7 days of osteogenic induction (7D-BMSCs-CM) induced the strongest M2 polarization in macrophages. Compared with the PBS group, 7D-BMSCs-CM induced the most significant polarization of Raw264.7 macrophages to the M2 type, and increased ARG-1 and CD163 expression to 1.36±0.09 and 1.69±0.09, respectively ( P<0.05), while decreasing iNOS and CD86 to 0.21±0.03 and 0.29±0.03 ( P<0.05). The absorbance values of macrophages in the 7D-BMSCs-exo group were significantly higher than those in the PBS group at 24 h, 48 h, and 72 h ( P<0.05). Compared with BMSCs-exo group, 7D-BMSCs-exo upregulated the expressions of CD163 and ARG-1 while inhibited the expressions of iNOS and CD86 ( P<0.05). Alizarin red staining showed enhanced mineral deposition and a higher degree of mineralization in the 7D-BMSCs-exo group, the staining intensity of ALP also increased simultaneously, the Western-blot results showed that the protein expressions of Runx2, ALP, OPN and OCN were respectively higher than those in the PBS group ( P<0.05). The results of the scratch assay showed that the relative migration distance of EPCs cells in the 7D-BMSCS-exo group at 24 h reached 2.30±0.05 μm, which was higher than that in the PBS group 1.10±0.02 μm ( P<0.05). The Tube formation experiment showed that the number of vascular rings in the EPCs group was higher than that in the PBS group (30.3±2.5 and 15.0±1.0, P<0.05), and the protein expressions of VEGF-A and PDGF were upregulated. Furthermore, the levels of phosphorylated P38 and ERK1/2 were significantly reduced in the 7D-BMSCs-exo group 0.40±0.06 and 0.25±0.06 compared with the PBS group ( P<0.05). Conclusions:Exosomes secreted by BMSCs during osteogenic differentiation promote the M2 polarization of Raw264.7 macrophages, with the most pronounced effect observed at the 7th day. M2-polarized macrophages, in turn, enhance the osteogenic differentiation of BMSCs and the angiogenic capacity of EPCs. These processes are closely associated with the suppression of the MAPK signaling pathway.

Objective:To investigate the effects of exosomes secreted by bone marrow mesenchymal stem cells (BMSCs) during osteogenic differentiation on the polarization of Raw264.7 macrophages and to elucidate the underlying mechanisms.Methods:PBS, uninduced BMSCs conditioned medium (CM), and osteogenic induction BMSCs CM for 7 d, 14 d, and 21 d were respectively added to Raw264.7 macrophages. After 48 h of treatment, Western blotting was used to detect and compare the expression of M1 markers of macrophages [inducible nitric oxide synthase (iNOS) and CD86] and M2 markers of macrophages [arginase-1 (ARG-1) and CD163] in each group. In addition, Raw264.7 macrophages were divided into three groups: the PBS group (only PBS added), the BMSCs-exo group (exosomes derived from uninduced BMSCs were added), and 7D-BMSCs-exo (exosomes derived from BMSCs were added after 7 days of osteogenic induction). The absorbance values of Raw264.7 cells in each group at 24 h, 48 h and 72 h were detected by an enzyme-linked immunosorbent assay (ELISA) reader. Western blotting was performed to assess changes of M1 or M2 marker proteins in Raw264.7 macrophages treated by exosome. The supernatants of the three groups of Raw264.7 macrophages were then co-cultured with BMSCs. Alizarin Red staining was used to quantify the formation of mineralized nodules, and alkaline phosphatase (ALP) staining was used to evaluate the osteogenic activity, and the expression levels of osteogenesis-related proteins Runx2, ALP, osteopontin (OPN), and osteocalcin (OCN) were detected. The migration ability of endothelial progenitor cells (EPCs) was detected by scratch assay for migration distance, and the angiogenesis ability was detected by in vitro tube formation assay for the number of vascular rings formed. The expressions of vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF) were detected by Western blot. The activation of the MAPK signaling pathway was evaluated by measuring phosphorylated and total P38 and ERK1/2 levels.Results:Western blot analysis showed that CM from BMSCs after 7 days of osteogenic induction (7D-BMSCs-CM) induced the strongest M2 polarization in macrophages. Compared with the PBS group, 7D-BMSCs-CM induced the most significant polarization of Raw264.7 macrophages to the M2 type, and increased ARG-1 and CD163 expression to 1.36±0.09 and 1.69±0.09, respectively ( P<0.05), while decreasing iNOS and CD86 to 0.21±0.03 and 0.29±0.03 ( P<0.05). The absorbance values of macrophages in the 7D-BMSCs-exo group were significantly higher than those in the PBS group at 24 h, 48 h, and 72 h ( P<0.05). Compared with BMSCs-exo group, 7D-BMSCs-exo upregulated the expressions of CD163 and ARG-1 while inhibited the expressions of iNOS and CD86 ( P<0.05). Alizarin red staining showed enhanced mineral deposition and a higher degree of mineralization in the 7D-BMSCs-exo group, the staining intensity of ALP also increased simultaneously, the Western-blot results showed that the protein expressions of Runx2, ALP, OPN and OCN were respectively higher than those in the PBS group ( P<0.05). The results of the scratch assay showed that the relative migration distance of EPCs cells in the 7D-BMSCS-exo group at 24 h reached 2.30±0.05 μm, which was higher than that in the PBS group 1.10±0.02 μm ( P<0.05). The Tube formation experiment showed that the number of vascular rings in the EPCs group was higher than that in the PBS group (30.3±2.5 and 15.0±1.0, P<0.05), and the protein expressions of VEGF-A and PDGF were upregulated. Furthermore, the levels of phosphorylated P38 and ERK1/2 were significantly reduced in the 7D-BMSCs-exo group 0.40±0.06 and 0.25±0.06 compared with the PBS group ( P<0.05). Conclusions:Exosomes secreted by BMSCs during osteogenic differentiation promote the M2 polarization of Raw264.7 macrophages, with the most pronounced effect observed at the 7th day. M2-polarized macrophages, in turn, enhance the osteogenic differentiation of BMSCs and the angiogenic capacity of EPCs. These processes are closely associated with the suppression of the MAPK signaling pathway.

Objective:To investigate the diagnosis and treatment significance of invasive and noninvasive operation for ventilator?as?sociated pneumonia ( VAP ) . Methods:A total of 80 cases of VAP suspected patients who had received mechanical ventilation at least 48 hours in ICU from Jun 2014 to Mar 2015 were enrolled. Patients were randomly divided into four groups including noninvasive operation group ( F) , invasive operation group ( Q) , mix group 1 ( H1) and mix group 2 ( H2) . VAP diagnosis rate between groups as well as living time, antibiotic use time, survival rate, calcitonin levels and APACHE II score, oxygenation index were analyzed. Results:Specimen from invasive operation had higher specimens to cultivate positive rate than that from noninvasive operation ( P<0?05), but there was no statistic significant difference in VAP diagnosis rate between two methods (P>0?05). Conclusion:Noninva?sive operation collecting samples for VAP diagnosis is also accurate as invasive one. Collecting specimens from sputum suction tube in the clinical treatment on airway suction is a low cost and simple noninvasive operation.

[ABSTRACT]AIM:ToobservehowfarnesoidXreceptor(FXR)functionedinconcanavalinA(ConA)-induced hepatitis (CIH) and the regulation of FXR-thyrotropin embryonic factor (TEF) pathway.METHODS:C57BL/6 mice were injected with Con A to induce hepatitis .The expression of FXR and TEF in the liver specimens was determined by qRT-PCR and Western blotting .The concentrations of serum ALT/AST and inflammatory cytokines IFN-γ, TNF-α, IL-4 and IL-2 in the blood samples were tested after Con A injection .RESULTS:FXR was down-regulated in CIH mice .TEF was up-regula-ted when FXR was activated by chenodeoxycholic acid (CDCA).Activation of FXR reduced the levels of aminotransferases and inflammatory cytokines IFN-γ, TNF-α, IL-4 and IL-2 in the CIH mice induced by Con A injection .CONCLUSION:FXR activation attenuates CIH mouse liver injury and reduces inflammatory cytokines .FXR activation results in TEF up-regu-lation.The FXR-TEF pathway may play a protective role in autoimmune hepatitis .