Human placenta derived mesenchymal stromal cells alleviate GVHD by promoting the generation of GSH and GST in PD-1+T cells.

AIMS: To investigate whether placenta-derived mesenchymal stromal cells (hPMSCs) have immunoregulatory effects on PD-1+ T cell generation by controlling ROS production and thus alleviating GVHD. MAIN METHODS: Flow cytometry was used to analyze the percentage of PD-1+ T cells, as well as the generation of ROS, GSH and GST in PD-1+ T cells. The expression of GST in the spleen and liver was analyzed by western blotting. KEY FINDINGS: The percentage of PD-1+ T cells was increased, but the ratio of GSH/GSSG was decreased in GVHD patients and the GVHDhigh mouse model compared with that in the normal control group. hPMSCs downregulated the level of malondialdehyde (MDA) and upregulated the ratio of GSH/GSSG and the expression of glutathione S transferase (GST) in the plasma, spleen and liver of GVHD mice compared with those of PBS-treated GVHD mice. Further studies showed that the ROS level, as well as the expression of PD-1, in both CD3+ and CD4+ T cells from the spleen and liver of hPMSC-treated GVHD mice were decreased compared with those observed in PBS-treated mice. SIGNIFICANCE: hPMSCs downregulated ROS generation by increasing GSH and GST levels and further reduced the expression of PD-1 on T cells, thereby alleviating inflammation in GVHD mice.

Study on preparation and property of a new adsorbent for endotoxin removal in blood purification / 生物医学工程学杂志

In order to remove the endotoxin from the blood of endotoxemia patients, we prepared a new adsorbent with heparin space arm and polymyxin B (PMB) ligand. The carrier of chloromethyl polystyrene resin was activated and heparin space arm was grafted, and then PMB ligand was immobilized onto adsorbent with glutaraldehyde. We employed in vitro FITC-lipopolysaccharide (FITC-LPS) static adsorption to characterize the adsorption properties on the adsorbent, and conducted in vitro lipopolysaccharide (LPS) static adsorption to measure quantitavely the adsorption capacity and rate, and then evaluated the blood compatibility. The in vitro static adsorption indicated that the adsorbent had the removal rate of LPS above 70% with the adsorption equilibrium time for 2 hours. Blood compatibility experiment showed that the adsorbent had little negative effects on blood cells and plasma protein, and their adsorption rates were less than 10% for hemocytes and 20% for plasma protein respectively. This adsorbent exhibited high selectivity, high adsorption capacity and good biocompatibility, and presented a promising clinical application in the treatment of endotoxemia.

Increased oxidative damages of erythrocytes caused by declined blood oxygen saturation / 生物医学工程学杂志

This paper was to explore the effect of blood oxygen saturation (SO2) on oxidative damages of erythrocytes under the condition of oxidative stress. Keeping SO2 of cultured erythrocytes in vitro at the states of 0.3, 0.5, 0.7, 0.9 and 0.98, respectively, we induced oxidative stress by tert-buthylhydroperoxide (BHP, 0.15 mmol/L of final concentration). After incubation, antioxidant capacity was assessed by measuring content of reduced glutathin hormone (GSH) in erythrocytes. Methemoglobin (MetHb) content, lipid peroxidation (thiobarbituric acid-reactive substances, TBARS) and denatured globin-chains on the plasma membrane were measured to assess the extent of oxidative damages. The results showed that in the presence of BHP, GSH contents increased from 0.3 to 0.98 groups; MetHb, TBARS and globin-chains levels all dropped with the rise of SO2. In conclusion, antioxidant capacity and oxidative damages of erythrocytes are closely related to SO2, declined SO2 could promote oxidative damages of erythrocytes.