There was no effective measures can be obtained at present to reverse or prevent airway remodeling. We investigated the therapeutic effect of Erythropoietin (EPO) gene modified mesenchymal stem cells (MSCs) on asthmatic airway remodeling and the possible underlied molecular mechanisms. EPO gene was transfected into MSCs via lentivirus vector. The transfected cells (EPO-MSCs) were identified by flow cytometry and the EPO secreting function was detected by PCR and Western blot. MSCs or EPO-MSCs were administrated to albumin (OVA)-induced chronic asthmatic mouse model via tail veins. The asthmatic phenotype was analyzed. Number of cells in bronchoalveolar lavage fluid (BALF) was counted using a hemocytometer. Histological findings of airways were evaluated by microscopic examination. The concentrations of interleukin 4(IL-4), interleukin 5(IL-5), and interleukin 13(IL-13) in lung homogenate were determined by ELISA. The activation state of transforming growth factor-β 1 (TGF-β1), Transforming growth factor beta-activated kinase 1 (TAK1), and p38 Mitogen Activated Protein Kinase (p38MAPK) signaling was detected by Real-Time PCR and Western blotting. EPO-MSCs were successfully constructed. EPO-MSCs showed a more potently suppressive effect on local asthmatic airway inflammation and the level of IL-4, IL-5, and IL-13 in lung tissue than MSCs. Moreover, the numbers of goblet cells, the thicknesses of smooth muscle layer, collagen density, percentage of proliferating cell nuclear antigen positive (PCNA ) mesenchymal cells, and von Willebrand factor positive(vWF ) vessels were also significantly inhibited by EPO-MSCs. Furthermore, EPO-MSCs could downregulate the expression of TGF-β1, TAK1, and p38MAPK in lung tissue both in mRNA level and in protein level. EPO gene modified MSCs may more efficiently attenuate asthmatic airway remodeling, which maybe related with the downregulation of TGF-β1-TAK1-p38MAPK pathway activity.

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In this paper, a geometrically-based single-bounce multiple-input-multiple-output (GBSB-MIMO) channel model is proposed for the long term evolution-metro (LTE-M) system in tunnel scenarios. The periodic slots of leaky coaxial cable (LCX) are equivalent to a series of magnetic dipoles. Based on the electric field distribution of the LCX, the theoretical model for line-of-sight (LOS) and non-line-of-sight (NLOS) propagation paths in the tunnel environment are derived. The measurement and simulation results are compared in terms of condition number (CN), channel capacity, and channel correlation function (CF), which verifies the feasibility and rationality of the new proposed model. The simulation results demonstrate, under such circumstances when the Ricean K-factor is smaller, the LCX spacing has a little influence on the channel capacity and CN due to a large number of the NLOS propagation paths in the tunnel, while as Ricean K-factor increases, the LCX spacing has more influence on the channel capacity and CN. By comparison of the measurement and simulation results, it was found that the capacity and CN of the LCX-MIMO is better than the dipole MIMO with different Ricean K-factor values, and under such conditions when the spacing between LCXs and the dipole antennas is increased. Therefore, this paper delivers an optimal system design for channel capacity based on the LCX deployment in the tunnel environment.INDEX TERMS Multiple-input multiple-output (MIMO), leaky coaxial cable (LCX), geometrically-based single-bounce (GBSB), tunnel, long term evolution-metro (LTE-M). KAI ZHANG received the B.S. degree in communication engineering from TaiShan University, Tai'an, China, in 2014, and the M.S. degree in signal and information processing from