Effect of bone marrow mesenchymal stem cells on the polarization of macrophages.

Inflammation is a defensive response in the living tissue of the vascular system that acts against damage factors and involves various types of immune cells, including macrophages, neutrophils, endothelial cells and other associated immune molecules. If the release of inflammatory mediators is excessive, systemic inflammatory response syndrome may develop. Sepsis is the most common complication of severe burns and is a systemic inflammatory response syndrome that is caused by infectious factors and is capable of leading to multiple organ dysfunction and potentially death. Research concerning the mechanism and treatment of sepsis is crucial. Macrophages are an important type of immune cell that remove invasive pathogens and are involved in innate and adaptive immune responses. It has been previously reported that bone marrow mesenchymal stem cells (BMSCs) affect macrophages by regulating immunity. The present study aimed to investigate the effect of BMSCs on macrophage polarization in vivo and in vitro, in addition to the potential therapeutic effect of these cells on experimental sepsis. BMSCs and peritoneal macrophages were isolated from Sprague­Dawley rats and co­cultured overnight as a mixed culture or Transwell system, and subsequently stimulated with 100 ng/ml lipopolysaccharide (LPS). After 12 h, the medium was replaced with normal complete medium for various durations and supernatants were collected to extract proteins and cells for ELISA, western blot and flow cytometry analysis to investigate different aspects of macrophages. Sepsis was induced in Sprague­Dawley rats by injection of LPS (5 mg/kg), followed by tail vein injection of BMSCs or PBS 1 h later. After 6, 12, 24 and 48 h, lung tissues were harvested for pathological observation and peritoneal macrophages were collected for flow cytometry analysis to assess the expression of markers, including cluster of differentiation (CD)68 (used for gating), CD11c and CD206. The results demonstrated that, in the culture medium, LPS stimulation increased the expression of CD11c in macrophages, and the levels of tumor necrosis factor­α and inducible nitric oxide synthase were also increased. By contrast, in macrophages treated with BMSCs directly, the expression of CD11c was reduced compared with the LPS­stimulated macrophage alone group. However, the secretion of interleukin­10, transforming growth factor­ß and arginase­1 was increased in the direct co­culture group, compared with the LPS­stimulated macrophage alone group. BMSCs reduced the inflammation in lung tissues and inhibited macrophage expression of CD11c in the rat model of sepsis. The results of the present study demonstrated that BMSCs co­cultured with macrophages directly inhibited macrophage differentiation into the M1 phenotype and reduced inflammation in macrophages stimulated by LPS. In vivo, BMSCs decreased the expression of CD11c in peritoneal macrophages and reduced the pathological inflammatory response in the lungs. The findings of the present study demonstrated that BMSCs may reduce the extent of the systemic inflammatory response, which may contribute to the development for a novel type of treatment for sepsis in the future.

Seasonal variations in the energy budget of Elliot's pheasant (Syrmaticus ellioti) in cage.

This study aimed to discuss the energy budget of Elliot's pheasant Syrmaticus ellioti in different seasons, with life and health, good growth and normal digestion of Elliot's pheasant as the tested objects, The energy budget of Elliot's pheasant was measured by daily collection of the trial pheasants' excrement in the biological garden of Guangxi Normal University from March 2011 to February 2012. The results showed that the gross energy consumption, metabolic energy and excrement energy varied by season, increasing as temperature decreased. There was significant difference in gross energy consumption, metabolic energy, excrement energy between adults and nonages. There was also a trend that food digestibility of pheasants increases as temperature increases. In the same season, the food digestibility of adults was better than that of nonages. Throughout spring, summer, autumn and winter, the metabolic energy of 4-year adults were 305.77±13.40 kJ/d, 263.67±11.89 kJ/d, 357.23±25.49 kJ/d and 403.12±24.91 kJ/d, respectively, and the nonages were 284.86±17.22 kJ/d, 284. 66±15.16 kJ/d, 402. 26±31.46 kJ/d and 420. 30±31.98 kJ/d, respectively. The minimum metabolic energies were 247.65±21.81 g, 265.86±26.53 g, respectively for each group, detected between 4-year adults and 1-year nonages. Further study is needed to determine whether 29.6 C is the optimal temperature for the Elliot's pheasant.

Metabolism and thermoregulation between Mrs Hume's Pheasant (Syrmaticus humiae) and Elliot's Pheasant (S. ellioti).

To understand metabolic adaptations, the basal metabolic rate (BMR) of Mrs Hume's Pheasant (Syrmaticus humiae) and Elliot's Pheasant (Syrmaticus ellioti) were investigated. Metabolic rate (MR), body temperature (T(b) ) and thermal conductance (C) were determined in both species at a temperatrue range of 5-35 Degrees Celsius, respectively. Oxygen consumption was measured with a closed circuit respirometer. The thermal neutral zones (TNZ) were 24.5-31.6 Degrees Celsius, and 23.0-29.2 Degrees Celsius, respectively. With a temperature range of 5-35 Degrees Celsius, Mrs Hume's Pheasant and Elliot's Pheasant could maintained stable T(b) at a mean of (40.47 ± 0.64) and (40.36 ± 0.10) Degrees Celsius, respectively. Mean BMRs within TNZs were (1.36 ± 0.84) mLO2/(g.h) for Mrs Hume's Pheasant and (2.03 ± 0.12) mLO2/(g.h) for Elliot's Pheasant, which were 77% and 86% of the expected value based on their body mass, respectively. Thermal conductance of Mrs Hume's Pheasant and Elliot's Pheasant were (0.12 ± 0.01) and (0.17 ± 0.01) mLO2/(g.h.Degrees Celsius), below the lower critical temperature, respectively, which were 119% and 124% of the expected value based on their body mass, respectively. The ecophysiological characteristics of these species were low metabolic rate, high body temperature, and high thermal conductance, which allow both species to better adapt to the warmer climate environment in south China.