Lactate-driven macrophage polarization in the inflammatory microenvironment alleviates intestinal inflammation.

Background: Lactate has long been considered an intermediate by-product of glucose metabolism. However, in recent years, accumulating evidence reveals that lactate has unique biological activities. In previous studies, lactate signaling was shown to inhibit inflammation. Furthermore, in vitro experiments have shown that lactate can promote the transformation of pro-inflammatory macrophages into anti-inflammatory macrophages. However, no in vivo studies have shown whether lactate can alleviate inflammation. Methods: RAW 264.7 macrophages were stimulated by LPS to induce an M1 phenotype, and cultured with low and high concentrations of lactate. The cells were then observed for phenotypic transformations and expression of inflammatory mediators and surface markers. The expression of inflammatory factors was also analyzed in the cell-free supernatant fraction. Further, a mouse model of DSS-induced colitis was established and treated with lactate. Colonic tissue injury was monitored by histopathological examinations. Results: The in vitro experiments showed that lactate promoted the transformation of activated macrophages to M2 phenotype and decreased the expression of TLR4-mediated NF-κB signaling proteins and inflammatory factors. In the DSS-induced colitis mouse model, lactate promoted the phenotypic transformation of macrophages in colonic tissue, reduced inflammation and organ damage, inhibited the activation of TLR4/NF-κB signaling pathway, decreased the serum levels of pro-inflammatory factors, increased the expression of anti-inflammatory factors, promoted the repair of the intestinal mucosal barrier and reduced the severity of colitis. Conclusions: Lactate inhibits the TLR/NF-κB signaling pathway and the production of pro-inflammatory factors by promoting polarization of macrophages. In addition, lactate promotesthe repair of the intestinal mucosal barrier and protects intestinal tissue in inflammation. Furthermore, lactate is relatively safe. Therefore, lactate is a promising and effective drug for treating inflammation through immunometabolism regulation.

A Temporal Examination of Cytoplasmic Ca2 + Levels, Sarcoplasmic Reticulum Ca2 + Levels, and Ca2 + -Handling-Related Proteins in Different Skeletal Muscles of Hibernating Daurian Ground Squirrels.

To explore the possible mechanism of the sarcoplasmic reticulum (SR) in the maintenance of cytoplasmic calcium (Ca2+) homeostasis, we studied changes in cytoplasmic Ca2+, SR Ca2+, and Ca2+-handling proteins of slow-twitch muscle (soleus, SOL), fast-twitch muscle (extensor digitorum longus, EDL), and mixed muscle (gastrocnemius, GAS) in different stages in hibernating Daurian ground squirrels (Spermophilus dauricus). Results showed that the level of cytoplasmic Ca2+ increased and SR Ca2+ decreased in skeletal muscle fiber during late torpor (LT) and inter-bout arousal (IBA), but both returned to summer active levels when the animals aroused from and re-entered into torpor (early torpor, ET), suggesting that intracellular Ca2+ is dynamic during hibernation. The protein expression of ryanodine receptor1 (RyR1) increased in the LT, IBA, and ET groups, whereas the co-localization of calsequestrin1 (CSQ1) and RyR1 in GAS muscle decreased in the LT and ET groups, which may increase the possibility of RyR1 channel-mediated Ca2+ release. Furthermore, calcium pump (SR Ca2+-ATPase 1, SERCA1) protein expression increased in the LT, IBA, and ET groups, and the signaling pathway-related factors of SERCA activity [i.e., ß-adrenergic receptor2 protein expression (in GAS), phosphorylation levels of phospholamban (in GAS), and calmodulin kinase2 (in SOL)] all increased, suggesting that these factors may be involved in the up-regulation of SERCA1 activity in different groups. The increased protein expression of Ca2+-binding proteins CSQ1 and calmodulin (CaM) indicated that intracellular free Ca2+-binding ability also increased in the LT, IBA, ET, and POST groups. In brief, changes in cytoplasmic and SR Ca2+ concentrations, SR RyR1 and SERCA1 protein expression levels, and major RyR1 and SERCA1 signaling pathway-related factors were unexpectedly active in the torpor stage when metabolic functions were highly inhibited.

Freestanding Na3V2O2(PO4)2F/Graphene Aerogels as High-Performance Cathodes of Sodium-Ion Full Batteries.

Although sodium vanadium fluorophosphate, Na3(VO1-xPO4)2F1+2x (0 ≤ x ≤ 1), is a highly promising cathode candidate for sodium-ion batteries because of its stable structure and high working voltage, the low charge diffusion dynamics and the inactive materials used in traditional coating electrodes reduce the energy density of a sodium-ion full battery. Hence, Na3V2O2(PO4)2F/graphene aerogels (NVPF/GAs) with a three-dimensional continuous porous network are first prepared by coassembly and freeze-drying. The three-dimensional porous network helps to obtain a high NVPF content of 81 wt %, relieve the volume change for improving the cyclability, and enhance the wettability of the electrode with the electrolyte for accelerating the diffusion dynamics of sodium ions and electrons. As a directly used freestanding cathode without the use of any binder/collector, an optimized freestanding NVPF/GA electrode exhibits excellent cycling and rate performances compared to traditional coating electrodes. The average capacities at current densities of 0.2, 0.5, 1.0, 2.0, and 5.0 C are 135.4, 128.0, 125.1, 121.9, and 115.1 mA h g-1, respectively. Especially, it maintains a capacity retention of 100% after 1000 cycles at an ultrahigh current of 40 C. A sodium-ion full battery with the NVPF/GA cathode and the Sb/graphene/carbon anode attains a of 82.1 mA h g-1 without an obvious decline after 100 cycles.

[Biological characteristics of rabbit bone marrow mesenchymal stem cells and their response to different growth factors].

This study was aimed to analyze the biological characteristics of rabbit bone marrow mesenchymal stem cells (rBM-MSCs) and their response to different growth factors. Rabbit BM-MSCs were separated from bone marrow mononuclear cells by using adherent cultivation. Biological characteristics were investigated by optical and electron microscopy. Immunophenotype of rBM-MSCs was measured by flow cytometry. The expression of collagen was detected by RT-PCR. Differentiation potential was identified by specific staining and RT-PCR. The response of rBM-MSCs to IL-1, 3, 8 and HGF with different concentrations were tested by MTT. The results showed that the rBM-MSCs gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast-like morphology and could be cultured for over 15 passages. CD44 was highly expressed on F5 rBM-MSCs (32%) and CD45 was lowly expressed (4.7%). Type I collagen was highly expressed, while type II collagen was lowly expressed and type X collagen was not detected on rBM-MSCs using RT-PCR method. In various conditions inducting differentiation, rBM-MSCs could differentiate into the osteoblast, chondrocyte, adipocyte and neuron-like cells. The rBM-MSCs were sensitive to IL-3, even low concentration (10 ng/ml) of IL-3 could promote the proliferation of rBM-MSCs effectively (>32%, P < 0.01), whereas high concentration IL-3 inhibited it significantly. It is concluded that rabbit BM-MSCs were successfully isolated and culture-expanded. The biological characteristics of rabbit BM-MSCs are similar to those of human and rhesus BM-MSCs. IL-3 with low concentration can promote the proliferation of rBM-MSCs effectively, but high concentration of IL-3 can inhibit their proliferation.

Double chimerism in recipient by transplantation of two allogeneic MHC-mismatched mouse fetal blood units.

We have constituted a mouse model for fetal blood transplantation (FBT) to cross over major histocompatibility complex (MHC) without causing serious GVHD. It seems that full matching at the MHC appears not necessary for FBT, while the nucleated cell dose is critical. Two fetal blood units were combined from different donors to increase the stem/progenitor cell dose so as to explore the possibility of MHC-mismatched allogeneic transplantation. 26 out of 40 mice in mixed FBT group survived in the observation period of 60 days after transplantation without obvious GVHD. Double chimerism was demonstrated by PCR and flow cytometric analysis; and skin transplantation test proved the induction of donor specific immune tolerance. Our data suggest that two MHC-mismatched allogeneic donor fetal blood units could simultaneously engraft and reconstitute immune and hematopoietic system in a mouse model. The result may be beneficial for the expansion of cord blood application and enables more patients to share the advantages of cord blood transplantation.

[Operating Procedure of Collection, Processing and Preservation of 3000 Units Umbilical Cord Blood in Shangdong Cord Blood Bank]

The experience with the umbilical cord blood (UCB) stem cells for unrelated transplantation from our 3 000 UCB storage was described. UCB, collected from closed blood bags, were mixed with hydroxyethyl starch for nucleated cell (NC) enrichment. After finishing CD34 analysis, culture of hematopoietic progenitors (CFU-GM and CFU-GEMM) assays, microbial culture, HLA Class I (A, B) serology and class II (DR) low resolution SSP typing, cord blood units are stored in the liquid nitrogen for clinical applicatoin. Cord blood contained an average of nuclear cell (NC) (1.2 +/- 0.6) x 10(9), CD34(+) cells (3.0 +/- 3.7) x 10(6), CFU-GM (1.1 +/- 0.7) x 10(6) and CFU-GEMM (1.1 +/- 1.2) x 10(6) for storage and the recovery rates were 91%, 88%, 85% and 82%, respectively. The recovery rates for red blood cell and Hb were (39 +/- 9)% and (40 +/- 8)%, respectively. The storage volume was (35.1 +/- 7.1) ml in a 50 ml storage bags. The mean time from collection to processing of 15 hours (range 4 - 24 hours) had no influence on cell viability. The cell viability before processing is more than 95% and 92% after UCB thawing. The recovery rates of NC, CD34(+) cells and CFU-GM post-thawing were 96%, 90% and 91%, respectively. There were no HIV antibody (HIVAb) positive in all of UCB units. For an incidence of processed samples, infection with syphilis, HBsAg, HBcAb, HCVAb, CMV, bacterial contamination and abnormal hemoglobin were 0.1%, 0.8%, 3.2%, 0.2%, 87.1%, 1.2% and 0.1%, respectively. More than 3 HLA loci matched can be found for random patients in our cord blood bank and 6 HLA loci matched have 5%. For transplantation with nucleated cell counts of > 2.7 x 10(7) cells/kg, our cord blood bank will be able to provide all of the umbilical cord blood stem cell samples for children and 50% of units can be used for some of adult recipients transplantation in the country. It is concluded that: (1) The large cord blood banking for 20 000 UCB storage is feasible in China. (2) Our system of whole procedure and methods is functionable for supplying qualified cord blood units in transplantation. (3) The volume for collection is critical to the yield of CD34(+) cells or hematopoietic progenitor cells, however cord blood NC is also important and proportional with CD34(+) cells. Only the units containing more than 8 x 10(8) cells and more than 60 ml of cord blood can be in the procession for storage.