Different responses to oxidized low-density lipoproteins in human polarized macrophages

<p>Abstract</p> <p>Background</p> <p>Oxidized low-density lipoprotein (oxLDL) uptake by macrophages plays an important role in foam cell formation. It has been suggested the presence of heterogeneous subsets of macrophage, such as M1 and M2, in human atherosclerotic lesions. To evaluate which types of macrophages contribute to atherogenesis, we performed cDNA microarray analysis to determine oxLDL-induced transcriptional alterations of each subset of macrophages.</p> <p>Results</p> <p>Human monocyte-derived macrophages were polarized toward the M1 or M2 subset, followed by treatment with oxLDL. Then gene expression levels during oxLDL treatment in each subset of macrophages were evaluated by cDNA microarray analysis and quantitative real-time RT-PCR. In terms of high-ranking upregulated genes and functional ontologies, the alterations during oxLDL treatment in M2 macrophages were similar to those in nonpolarized macrophages (M0). Molecular network analysis showed that most of the molecules in the oxLDL-induced highest scoring molecular network of M1 macrophages were directly or indirectly related to transforming growth factor (TGF)-β1. Hierarchical cluster analysis revealed commonly upregulated genes in all subset of macrophages, some of which contained antioxidant response elements (ARE) in their promoter regions. A cluster of genes that were specifically upregulated in M1 macrophages included those encoding molecules related to nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) signaling pathway. Quantitative real-time RT-PCR showed that the gene expression of interleukin (IL)-8 after oxLDL treatment in M2 macrophages was markedly lower than those in M0 and M1 cells. <it>HMOX1 </it>gene expression levels were almost the same in all 3 subsets of macrophages even after oxLDL treatment.</p> <p>Conclusions</p> <p>The present study demonstrated transcriptional alterations in polarized macrophages during oxLDL treatment. The data suggested that oxLDL uptake may affect TGF-β1- and NF-κB-mediated functions of M1 macrophages, but not those of M0 or M2 macrophages. It is likely that M1 macrophages characteristically respond to oxLDL.</p

Osteopontin as a Mediator of NKT Cell Function in T Cell-Mediated Liver Diseases

AbstractBoth osteopontin (OPN) and natural killer T (NKT) cells play a role in the development of immunological disorders. We examined a functional link between OPN and NKT cells. Concanavalin A (Con A)-induced hepatitis is a well-characterized murine model of T cell-mediated liver diseases. Here, we show that NKT cells secrete OPN, which augments NKT cell activation and triggers neutrophil infiltration and activation. Thus, OPN- and NKT cell-deficient mice were refractory to Con A-induced hepatitis. In addition, a neutralizing antibody specific for a cryptic epitope of OPN, exposed by thrombin cleavage, ameliorated hepatitis. These findings identify NKT cell-derived OPN as a novel target for the treatment of inflammatory liver diseases

Type II NKT Cells Stimulate Diet-Induced Obesity by Mediating Adipose Tissue Inflammation, Steatohepatitis and Insulin Resistance

The progression of obesity is accompanied by a chronic inflammatory process that involves both innate and acquired immunity. Natural killer T (NKT) cells recognize lipid antigens and are also distributed in adipose tissue. To examine the involvement of NKT cells in the development of obesity, C57BL/6 mice (wild type; WT), and two NKT-cell-deficient strains, Jα18−/− mice that lack the type I subset and CD1d−/− mice that lack both the type I and II subsets, were fed a high fat diet (HFD). CD1d−/− mice gained the least body weight with the least weight in perigonadal and brown adipose tissue as well as in the liver, compared to WT or Jα18−/− mice fed an HFD. Histologically, CD1d−/− mice had significantly smaller adipocytes and developed significantly milder hepatosteatosis than WT or Jα18−/− mice. The number of NK1.1+TCRβ+ cells in adipose tissue increased when WT mice were fed an HFD and were mostly invariant Vα14Jα18-negative. CD11b+ macrophages (Mφ) were another major subset of cells in adipose tissue infiltrates, and they were divided into F4/80high and F4/80low cells. The F4/80low-Mφ subset in adipose tissue was increased in CD1d−/− mice, and this population likely played an anti-inflammatory role. Glucose intolerance and insulin resistance in CD1d−/− mice were not aggravated as in WT or Jα18−/− mice fed an HFD, likely due to a lower grade of inflammation and adiposity. Collectively, our findings provide evidence that type II NKT cells initiate inflammation in the liver and adipose tissue and exacerbate the course of obesity that leads to insulin resistance

A new approach to stabilize waste biomass for valorization using an oxidative process at 90 °C

This study aimed to establish a new methodology for upgrading biomass quality using low-temperature (below 100 degrees C) oxidation to achieve simultaneous drying and decomposition. Sterilized manure (63% wet basis) was heated at 90 degrees C for 49 days under an oxidative environment. The obtained solid and moisture reduction curves indicated that drying and decomposition proceeded simultaneously. The biomass was decomposed by oxidation with the release of water, carbon dioxide, and volatile fatty acids such as acetic acid. The oxidation process stopped when the biomass was dehydrated, indicating that the water originally present in the biomass governed the process. Elemental and calorific analyses revealed no remarkable increase in carbon content or increased heating value, and a slight decrease in oxygen content. Although the severity of the process was insufficient to produce an optimum solid fuel due to the low temperature used, the process would enable the stabilization of waste biomass with low energy consumption such as using waste heat

Release of essential plant nutrients from manure- and wood-based biochars

Several biochars have a considerable amount of essential plant nutrients; however, the release of those nutrients in soil is not well understood. Therefore, in this study, six biochars with varying nutrient contents were produced from Japanese larch (Larix kaempferi, JL), dairy manure (DM), and chicken manure (CM) at 300 and 500 °C and incubated in a temperate clay loam soil to investigate their nutrient release dynamics. The available N, P, and K release patterns of the biochars (2% dry-basis) were compared with the recommended fertilizer dose of sweet corn (Zea mays convar. saccharata) for 120 days. The results indicated that only chicken manure biochars (C/N ratio < 8) have the potential to satisfy plant needs by releasing sufficient N, P, and K. Fourier-transform infrared analysis revealed that N-containing amide dissolution was the major mechanism behind the 49% N release from the CM300 biochar. A higher production temperature (500 °C) diminished most of these amides, resulting in lower N release from CM500 (8.9%). Nitrification-induced reduction of soil pH caused Ca/Mg-P dissolution from manure biochars and enhanced P release. Much of the released phosphates later became unavailable in the soil by aluminosilicate complex formation. DM biochar also released adequate P and K, and production at 500 °C generally performed better than at 300 °C. Effect of coexisting ions on some nutrient release was found, though was statistically nonsignificant. Overall, results revealed that low-temperature (≤500 °C) CM and DM biochars can become comprehensive or complementary sources of plant nutrients, respectively, with some enhanced nutrient-retaining potential, although inherent soil properties may play a significant role

Role of ambient pressure in self-heating torrefaction of dairy cattle manure

This paper describes the role of ambient pressure in self-heating torrefaction of livestock manure. We explored the initiating temperatures required to cause self-heating of wet dairy cattle manure at different ambient pressures (0.1, 0.4, 0.7, and 1.0 MPa). Then, we conducted proximate, elemental, and calorific analyses of biochar torrefied at 210, 250, and 290°C. The results showed that self-heating was induced at 155°C or higher for 0.1 MPa and at 115°C or lower for 0.4 MPa or higher. The decrease of the initiating temperature at elevated pressure was due not only to more oxygen, but also to the retention of moisture that can promote chemical oxidation of manure. Biochar yields decreased with increasing torrefaction temperature and pressure, and the yield difference at 0.1 and 1.0 MPa was more substantial at lower temperatures: a 29.8, 16.4, and 9.4% difference at 210, 250, and 290°C, respectively. Proximate and elemental analyses showed that elevated pressure promotes devolatilization, deoxygenation, and coalification compared to atmospheric pressure; its impact, however, was less at higher temperatures as the torrefaction temperature became more dominant. Calorific analysis revealed that elevated pressure can increase the higher heating value (HHV) on a dry and ash-free basis at 210°C because of the increase in carbon content, but its impact is limited at 250 and 290°C. Meanwhile, the HHV on a dry basis exhibited the opposite trend due primarily to an enlargement of ash content. The present study revealed that ambient pressure considerably affects the initiating temperature of self-heating and the chemical properties of biochar at a low torrefaction temperature

A new torrefaction system employing spontaneous self-heating of livestock manure under elevated pressure

This report describes a new oxidative torrefaction method employing spontaneous self-heating of feed-stock as a means of overcoming practical difficulties in converting livestock manure to biochar. We examined the initiating temperature required to induce self-heating of wet dairy cattle manure under 1.0 MPa pressure and conducted elemental and calorific analyses of the solid products prepared at 200, 250, and 300C°. Self-heating was initiated with oxidation below 100C°, and the lower limit of the initiation temperature was between 85 and 90C°. Comparing processes performed at 0.1 and 1.0 MPa, the higher pressure promoted self-heating by both preventing heat loss due to moisture evaporation occurring at approximately 100C° and supplying oxygen to the high-moisture feedstock. In addition, as drying occurred at 160-170C° during the process, the system did not require pre- or post-drying. Although the heating values of the solid products decreased due to high ash content, the elemental composition of the products was altered to that of peat-like (200C°) and lignite-like (250 and 300C°) materials. Cessation of self-heating of the manure is recommended at approximately 250C° to avoid severe decomposition at higher temperatures. Overall, these results demonstrated the utility of the proposed method for converting wet manure into dried biochar through self-heating as well as potential applications in manure management systems. © 2019 The Authors. Published by Elsevier Ltd

Th1 or Th2 balance regulated by interaction between dendritic cells and NKT cells

If Th1 or Th2 polarization could be artificially manipulated, effective immune responses would be generated depending on nature of the targets. In this study we attempted to regulate CD40 expressions on dendritic cells (DCs) in order to modify the T cell response. It was found that reducing agents selectively inhibited surface expression of CD40 on DCs. This finding may provide a new strategy of DC-mediated modulation of the Th1/Th2 balance. It was also shown that NKT-produced Th1/Th2 cytokine balance was under control of negative feedback loop through DCs. Th1 cytokine-pretreated DCs mainly induced Th2 cytokine production, whereas Th2 cytokine-pretreated DCs induced Th1 cytokine production by α-galactosylceramide-stimulated NKT cells. The negative feedback regulation system could be applicable to therapeutics of various diseases based on immunological disorders