Plastic film mulching application improves potato yields, reduces ammonia emissions, but boosts the greenhouse gas emissions in China.

With global population growth and climate change, food security and global warming have emerged as two major challenges to agricultural development. Plastic film mulching (PM) has long been used to improve yields in rain-fed agricultural systems, but few studies have focused on soil gas emissions from mulched rainfed potatoes on a long-term and regional scale. This study integrated field data with the Denitrification-Decomposition (DNDC) model to evaluate the impacts of PM on potato yields, greenhouse gas (GHG) and ammonia (NH3) emissions in rainfed agricultural systems in China. We found that PM increased potato yield by 39.7 % (1505 kg ha-1), carbon dioxide (CO2) emissions by 15.4 % (123 kg CO2 eq ha-1), nitrous oxide (N2O) emissions by 47.8 % (1016 kg CO2 eq ha-1), and global warming potential (GWP) by 38.9 % (1030 kg CO2 eq ha-1), while NH3 volatilization decreased by 33.9 % (8.4 kg NH3 ha-1), and methane (CH4) emissions were little changed compared to CK. Specifically, the yield after PM significantly increased in South China (SC), North China (NC), and Northwest China (NWC), with increases of 66.1 % (2429 kg ha-1), 44.1 % (1173 kg ha-1), and 43.6 % (956 kg ha-1) compared to CK, respectively. The increase in GWP and greenhouse gas emission intensity (GHGI) under PM was more pronounced in the Northeast China (NEC) and NWC regions, with respective increases of 57.1 % and 60.2 % in GWP, 16.9 % and 10.3 % in GHGI. While in the Middle and Lower reaches of the Yangtze River (MLYR) and SC, PM decreased GHGI with 10.2 % and 31.1 %, respectively. PM significantly reduced NH3 emissions in all regions and these reductions were most significant in Southwest China (SWC), SCand MLYR, which were 41 %, 38.0 %, and 38.0 % lower than CK, respectively. In addition, climatic and edaphic variables were the main contributors to GHG and NH3 emissions. In conclusion, it is appropriate to promote the use of PM in the MLYR and SC regions, because of the ability to increase yields while reducing environmental impacts (lower GHGI and NH3 emissions). The findings provide a theoretical basis for sustainable agricultural production of PM potatoes.

Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-ß and IL-6 Expression of Human Corneal Fibroblasts, In Vitro.

PURPOSE: To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor ß1 (TGF-ß1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT). METHODS: HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-ß1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA. RESULTS: TGF-ß1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-ß1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-ß1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups. CONCLUSIONS: Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-ß1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-ß1 and IL-6 protein level after 24 h.

Human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium.

PURPOSE: To investigate human corneal epithelial cell and fibroblast migration and growth factor secretion after rose bengal photodynamic therapy (RB-PDT) and the effect of conditioned medium (CM). METHODS: A human corneal epithelial cell line (HCE-T), human corneal fibroblasts (HCF) and keratoconus fibroblasts (KC-HCF) have been used. Twenty-four hours after RB-PDT (0.001% RB concentration, 565 nm wavelength illumination, 0.17 J/cm2 fluence) cell migration rate using scratch assay and growth factor concentrations in the cell culture supernatant using ELISA have been determined. In addition, the effect of CM has been observed. RESULTS: RB-PDT significantly reduced migration rate in all cell types, compared to controls (p≤0.02). Migration rate of HCE-T cultures without RB-PDT (untreated) was significantly higher using HCF CM after RB-PDT, than using HCF CM without RB-PDT (p<0.01). Similarly, untreated HCF displayed a significantly increased migration rate with HCE-T CM after RB-PDT, compared to HCE-T CM without treatment (p<0.01). Furthermore, illumination alone and RB-PDT significantly decreased keratinocyte growth factor (KGF) concentration in HCF and KC-HCF supernatant, and RB-PDT significantly decreased soluble N-Cadherin (SN-Cad) concentration in HCF supernatant, compared to controls (p<0.01 for all). In HCE-T CM, RB-PDT increased hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGFb) concentration (p≤0.02), while decreasing transforming growth factor ß (TGF-ß) concentration (p<0.01). FGFb concentration increased (p<0.0001) and TGF-ß concentration decreased (p<0.0001) in HCF CM, by RB-PDT. Epidermal growth factor (EGF), HGF, and TGF-ß concentration decreased (p≤0.03) and FGFb concentration increased (p<0.01) in KC-HCF CM, using RB-PDT. CONCLUSIONS: HCE-T, HCF and KC-HCF migration rate is reduced 24 hours after RB-PDT. In contrast, HCE-T migration is enhanced using HCF CM after RB-PDT, and HCF migration rate is increased through HCE-T CM following RB-PDT. Modulation of EGF, KGF, HGF, FGFb, TGF-ß and N-Cadherin secretion through RB-PDT may play an important role in corneal wound healing.

[Differential proteomic analysis of rat hepatic stellate cells treated by oxymatrine liposomes using two-dimensional electrophoresis].

OBJECTIVE: To analyze differentially expressed proteins of hepatic stellate cells (HSCs) treated with oxymatrine (OMT) liposomes, thus further exploring the molecular mechanism of OMT liposomes for treating liver fibrosis. METHODS: A rat model of CCl4 induced chronic liver fibrosis was established. HSCs were perfusion isolated from modeled SD rats and cultured in vitro . Passage 2 HSCs were divided into the model group (Group A), the OMT-liposome-treated group (Group B), and the liposome-treated control group (Group C). HSCs from normal rats were taken as the normal control group (Group D). The total proteins of HSCs cells were extracted from Group B and D after 7 days of treatment, and separated with isoelectrofocusing two-dimensional electrophoresis (2-DE). A 2-DE system was established to analyze the differences in the protein profile between Group B and Group C. Tow protein dots with most obvious difference were selected to determine the structures and functions of different proteins using peptide mass fingerprinting (PMF). RESULTS: (1) The total number bf proteins decreased after treated with OMT liposomes, with 864 spots before treatment and 756 spots after treatment, and the matching rate was 63%. (2) According to 2-DE results, 10 differential protein spots were found by image analysis of magnifying images in local regions. (3) Two most differently expressed proteins were identified to be ATM (46. 236 kD) and Miz1 (54. 051 kD) by PMF and SWISS-PROT protein database retrieval. CONCLUSION: Action of OMT liposomes on HSCs of rats with chronic liver fibrosis caused different protein expressions, which might be involved in the signaling pathways of inducing the apoptosis of HSCs.

[Oxymatrine could promote mesenchymal stem cell therapy in hepatic fibrosis rats: an experimental research].

OBJECTIVE: To investigate whether oxymatrine (OM) could promote mesenchymal stem cell (MSC) therapy in CCl4-induced hepatic fibrosis (HF) in rats and to initially explore its mechanisms. METHODS: Totally 50 male SD rats were randomly divided into five groups,i.e., the normal control group, the model group, the MSC therapy group, the OM therapy group, and the MSC combined OM therapy group, 10 in each group. Except the normal control group, the HF model was duplicated by CCl4 induction. After successful modeling, rats in the MSC therapy group received 5 x10(6) MSCs by intravenous injection via caudal vein, once a week. Rats in the OM therapy group received 50 mg/kg OM by intramuscular injection, three times a week. Rats in MSC combined OM therapy group received 5 x 10(6) MSCs by intravenous injection via caudal vein, once a week and 50 mg/kg OM by intramuscular injection three times a week. Equal volume of normal saline was given to those in the normal control group and the model group. All medication lasted for 8 weeks. Serum levels of ALT and AST were detected 8 weeks later. The hepatic histopathological injury and extracellular matrix deposit were assessed using HE and Masson staining. Expressions of serum interleukin-4 (IL-4) and interleukin-10 (IL-10) were detected using enzyme linked immunosorbent assay (ELISA). RESULTS: (1) Compared with the normal control group, serum levels of ALT and AST significantly increased in the model group (P < 0.05). Compared with the model group, serum levels of ALT and AST significantly decreased in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group at the end of 8 weeks of treatment (P < 0.05). But serum levels of ALT and AST were significantly lower in the MSC combined OM therapy group than in the OM therapy group and the MSC therapy group (P < 0.05). (2) Compared with the model group, the hepatic injury was significantly lessened and the area of extracellular matrix deposit was significantly reduced in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group (P < 0.05). Besides, they wer more significant in the MSC combined OM therapy group (P < 0.05). (3) Compared with the model group, the serum IL-4 level was significantly higher in the MSC therapy group and the MSC combined MO group (P < 0.05). It was higher in the MSC combined MO group (P < 0.05). Although the serum IL-4 level also increased in the OM therapy group, but with no statistical difference (P > 0.05). (4) The serum IL-10 level significantly increased in the OM therapy group, the MSC therapy group, and the MSC combined OM therapy group (P < 0.05), and it was the highest in the MSC combined OM therapy group among the three groups (P < 0.05). (5) Two-photon fluorescence imaging showed no signals of MSCs in liver with or without OM injection. CONCLUSION: OM could promote mesenchymal stem cell therapy in hepatic fibrosis rats, which might be involved in increasing serum levels of IL-4 and IL-10.