Prevention of the Lachnum polysaccharide and its selenium derivatives on cisplatin-induced acute kidney injury in mice.

To investigate the renal protective effects of the polysaccharide LEP-1a and derivatives of selenium (SeLEP-1a) from Lachnum YM38, cisplatin (CP) was used to establish an acute kidney model. LEP-1a and SeLEP-1a could effectively reverse the decrease in renal index and improved renal oxidative stress. LEP-1a and SeLEP-1a significantly reduced the contents of the inflammatory cytokines. They could inhibit the release of cyclooxygenase 2 (COX-2) and nitric oxide synthase (iNOS) and increase the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1). At the same time, the PCR results indicated that SeLEP-1a could significantly inhibit the mRNA expression levels of toll-like receptor 4 (TLR4), nuclear factor-kB (NF-κB) p65 and inhibitor of kappa B-alpha (IκBα). Western blot analysis showed that LEP-1a and SeLEP-1a significantly downregulated the expression levels of Bcl-2-associated X protein (Bax) and cleaved caspase-3 and upregulated phosphatidylinositol 3-kinase (p-PI3K), protein kinase B (p-Akt) and B-cell lymphoma 2 (Bcl-2) protein expression levels in the kidney. LEP-1a and SeLEP-1a could improve CP-induced acute kidney injury by regulating the oxidative stress response, NF-κB-mediated inflammation and the PI3K/Akt-mediated apoptosis signalling pathway.

Investigation of the spatial heterogeneity of soil microbial biomass carbon and nitrogen under long-term fertilizations in fluvo-aquic soil.

Soils are heterogeneous and microbial spatial distribution can clearly indicate the spatial characteristics of the soil carbon and nitrogen cycle. However, it is not clear how long-term fertilization affects the spatial distribution of microbial biomass in fluvo-aquic soil. We collected fluvo-aquic soil samples (topsoil 0-7.5 cm and sub-topsoil 7.5-20 cm) using a spatially-explicit design within three 40.5 m2 plots in each of four fertilization treatments. Fertilization treatments were: cropping without fertilizer inputs (CK); chemical nitrogen, phosphorus, and potassium fertilizer (NPK); chemical fertilizer with straw return (NPKS); and chemical fertilizer with animal manure (NPKM). Variables included soil microbial biomass carbon (MBC) and nitrogen (MBN), and MBC/MBN. For both soil layers, we hypothesized that: microbial biomass was lowest in CK but with the largest spatial heterogeneity; and microbial biomass was highest in NPKM and NPKS but with the lowest spatial heterogeneity. Results showed that: (1) Fertilization significantly increased MBC and MBN more in topsoil than sub-topsoil but had no MBC/MBN changes. (2) The coefficient of variation (CV) and Cochran's C showed that variation was largest in CK in topsoil and NPK in sub-topsoil and that variation of topsoil was generally lower than in sub-topsoil. The sample size of the three variables was largest in CK in topsoil but had little variation among the other treatments. (3) The trend-surface model showed that within-plot heterogeneity varied substantially with fertilization (NPKM = NPK > NPKS > CK), but Moran's I and the interpolation map showed that spatial variability with fertilization followed the order NPK > NPKS > CK = NPKM at a fine scale in topsoil. In sub-topsoil, the trend-surface model showed that within-plot heterogeneity followed the order NPKM = CK > NPK > NPKS and that the fine-scale pattern was NPKM>NPK = NPKS>CK. MBC had the highest spatial heterogeneity among the three variables in both soil layers. Our results indicate that the application of organic fertilizer (straw or manure) reduced the variation of MBC and MBN but increased the spatial variability of MBC and MBN. The spatial variation of the three variables was MBC > MBN > MBC/MBN regardless of whether variation was considered at the plot-scale or the fine-scale in both layers.