Project description:The sepsis-induced acute lung injury (ALI) still represents one of the leading causes of death in critically ill patients, underscoring the need for novel therapies. Excessive activation of immune cells and damage of reactive oxygen species (ROS) are the main factors that exacerbate lung injury. Here, the multifaceted immunomodulatory nanocomplexes targeting the proinflammatory neutrophilic activation and ROS damage are established. The S100A8/9 inhibitor, ABR2575, is loaded in the nanocomplexes, which effectively blocks the neutrophils-S100A8/A9- toll-like receptors (TLRS)-Inflammasome signaling in ALI. Synergically, the SiH nanosheets are encapsulated together with ABR2575 into the core of poly(lactic-co-glycolic acid) (PLGA) nanosponges, to achieve sustainable hydrogen release for the alleviation of ROS-induced lung tissue injury, and also promote the M2 polarization of macrophages. This novel combination strategy is proven to significantly suppress the infiltration of neutrophils and pro-inflammatory macrophages into the lungs, decrease the activation of neutrophils and pro-inflammatory monocytes in the blood, facilitate the anti-inflammatory polarization of macrophages and monocytes, and reduce the expression of pro-inflammatory cytokines in both the lung and blood circulation, all of which alleviate the lung injuries in preclinical murine ALI models. The current investigations offer a novel nanomedicine for the treatment of ALI with great potential in clinical invention.
Project description:Peripheral serotonin (5-HT) is mainly generated from the gastrointestinal tract and taken up and stored by platelets in the circulation. Although the gut is recognized as a major immune organ, how intestinal local immune responses control whole-body physiology via 5-HT remains unclear. Here, we show that intestinal inflammation enhances systemic platelet activation and blood coagulation. Intestinal epithelium damage induces elevated levels of the alarm cytokine interleukin-33 (IL-33), leading to platelet activation via promotion of gut-derived 5-HT release. More importantly, we found that loss of intestinal epithelial-derived IL-33 lowers peripheral 5-HT levels, resulting in compromised platelet activation and hemostasis. Functionally, intestinal IL-33 contributes to the recruitment of neutrophils to sites of acute inflammation by enhancing platelet activities. Genetic deletion of intestinal IL-33 or neutralization of peripheral IL-33 protects animals from lipopolysaccharide endotoxic shock through attenuated neutrophil extravasation. Therefore, our data establish a distinct role of intestinal IL-33 in activating platelets by promoting 5-HT release for systemic physiology and inflammation.
Project description:1. Mammary tissue was obtained from rabbits at various stages of pregnancy and lactation and used for tissue-slice incubations (to measure the rate of fatty acid synthesis and CO(2) production) and to determine relevant enzymic activities. A biphasic adaptation in fatty acid synthetic capacity during lactogenesis was noted. 2. The first lactogenic response occurred between day 15 and 24 of pregnancy. Over this period fatty acid synthesis (from acetate) increased 14-fold and the proportions of fatty acids synthesized changed to those characteristic of milk fat (77-86% as C(8:0)+C(10:0) acids). 3. The second lactogenic response occurred post partum as indicated by increased rates of fatty acid synthesis and CO(2) production (from acetate and glucose) and increased enzymic activities. 4. Major increases in enzymic activities between mid-pregnancy and lactation were noted for ATP citrate lyase (EC 4.1.3.8), acetyl-CoA synthetase (EC 6.2.1.1), acetyl-CoA carboxylase (EC 6.4.1.2), fatty acid synthetase, glucose 6-phosphate dehydrogenase (EC 1.1.1.49), and 6-phosphogluconate dehydrogenase (EC 1.1.1.44). Smaller increases in activity occurred with glycerol 3-phosphate dehydrogenase (EC 1.1.1.8) and NADP(+)-isocitrate dehydrogenase (EC 1.1.1.42) and the activity of NADP(+)-malate dehydrogenase (EC 1.1.1.40) was negligible at all periods tested. 5. During pregnancy and lactation there was a close temporal relationship between fatty acid synthetic capacity and the activities of ATP citrate lyase (r=0.94) and acetyl-CoA carboxylase (r=0.90).
Project description:Oxygen availability, along with the abundance of nutrients (such as glucose, glutamine, lipids and albumin), fluctuates significantly during tumour evolution and the recruitment of blood vessels, leukocytes and reactive fibroblasts to complex tumour microenvironments. As such, hypoxia and concomitant nutrient scarcity affect large gene expression programmes, signalling pathways, diverse metabolic reactions and various stress responses. This Review summarizes our current understanding of how these adaptations are integrated in hypoxic tumour cells and their role in disease progression.
Project description:Metastasis-initiating cells dynamically adapt to the distinct microenvironments of different organs, but these early adaptations are poorly understood due to the limited sensitivity of in situ transcriptomics. We developed fluorouracil-labeled RNA sequencing (Flura-seq) for in situ analysis with high sensitivity. Flura-seq utilizes cytosine deaminase (CD) to convert fluorocytosine to fluorouracil, metabolically labeling nascent RNA in rare cell populations in situ for purification and sequencing. Flura-seq revealed hundreds of unique, dynamic organ-specific gene signatures depending on the microenvironment in mouse xenograft breast cancer micrometastases. Specifically, the mitochondrial electron transport Complex I, oxidative stress and counteracting antioxidant programs were induced in pulmonary micrometastases, compared to mammary tumors or brain micrometastases. We confirmed lung metastasis-specific increase in oxidative stress and upregulation of antioxidants in clinical samples, thus validating Flura-seq's utility in identifying clinically actionable microenvironmental adaptations in early metastasis. The sensitivity, robustness and economy of Flura-seq are broadly applicable beyond cancer research.
Project description:AimsInflammation is a pivotal characteristic of neurodegenerative diseases. The triggering receptor expressed on the myeloid cells 2 (TREM2) gene has previously been shown to suppress inflammation by directly inhibiting inflammation-related pathways. Mitochondrial dysfunction has recently emerged as another critical pathological manifestation of neurodegenerative diseases. Although TREM2 is involved in the regulation of cellular energy metabolism and mitochondrial autophagy, its role in the relationship between inflammation and mitochondrial autophagy remains unclear.MethodsIn this study, we generated TREM2-overexpressing BV-2 cells and established a neuroinflammatory model with LPS. We compared these cells with wild-type cells in terms of inflammation, metabolism, autophagy, and mitochondria using methods such as RT-qPCR, Western blotting, immunocytochemistry, transmission electron microscopy, and flow cytometry.ResultsMicroglia overexpressing TREM2 exhibited increased resistance to inflammation. Additionally, these cells inhibited the metabolic reprogramming that occurs early in LPS-induced inflammation, reduced ROS release, mitigated mitochondrial damage, maintained a certain level of autophagic activity, and cleared damaged mitochondria. Consequently, they alleviated the inflammation caused by the mitochondrial barrier.Conclusionsur results suggest that TREM2 can alleviate inflammation by maintaining cellular metabolic homeostasis and mitochondrial autophagy activity.
Project description:1. Mammary-tissue biopsies were obtained from multiparous cows at 30 and 7 days pre partum and 7 and 40 days post partum. Investigations of the effect of lactogenesis on fatty acid and lactose synthesis involved measurements of biosynthetic capacity (tissue-slice incubations in vitro) and activities of relevant enzymes. 2. Fatty acid synthesis from acetate increased over 20-fold from 30 days pre partum to 40 days post partum. Changes in the lipogenic capacity of mammary-tissue slices more closely paralleled increases in the activities of acetyl-CoA carboxylase (EC 6.4.1.2) and acetyl-CoA synthetase (EC 6.2.1.1) than of other enzymes involved in acetate incorporation into fatty acids or in NADPH generation. 3. Lactose biosynthesis by mammary-tissue slices, lactose synthetase activity (EC 2.4.1.22) and alpha-lactalbumin concentration were all negligible at 30 days pre partum but increased 2.5-4-fold between 7 days pre partum and 40 days post partum. Phosphoglucomutase (EC 2.7.5.1), UDP-glucose pyrophosphorylase (EC 2.7.7.9) and UDP-glucose 4-epimerase (EC 5.1.3.2) had substantial activities at 30 days pre partum and increased less dramatically during lactogenesis. 4. Results are consistent with acetyl-CoA carboxylase and perhaps acetyl-CoA synthetase representing the regulatory enzyme(s) in fatty acid synthesis, with lactose synthetase (alpha-lactalbumin) serving a similar function in lactose biosynthesis.
Project description:Streptococcus pneumoniae (pneumococcus) is one of the primary bacterial pathogens that complicates influenza virus infections. These bacterial coinfections increase influenza-associated morbidity and mortality through a number of immunological and viral-mediated mechanisms, but the specific bacterial genes that contribute to postinfluenza pathogenicity are not known. Here, we used genome-wide transposon mutagenesis (Tn-Seq) to reveal bacterial genes that confer improved fitness in influenza virus-infected hosts. The majority of the 32 genes identified are involved in bacterial metabolism, including nucleotide biosynthesis, amino acid biosynthesis, protein translation, and membrane transport. We generated mutants with single-gene deletions (SGD) of five of the genes identified, SPD1414, SPD2047 (cbiO1), SPD0058 (purD), SPD1098, and SPD0822 (proB), to investigate their effects on in vivo fitness, disease severity, and host immune responses. The growth of the SGD mutants was slightly attenuated in vitro and in vivo, but each still grew to high titers in the lungs of mock- and influenza virus-infected hosts. Despite high bacterial loads, mortality was significantly reduced or delayed with all SGD mutants. Time-dependent reductions in pulmonary neutrophils, inflammatory macrophages, and select proinflammatory cytokines and chemokines were also observed. Immunohistochemical staining further revealed altered neutrophil distribution with reduced degeneration in the lungs of influenza virus-SGD mutant-coinfected animals. These studies demonstrate a critical role for specific bacterial genes and for bacterial metabolism in driving virulence and modulating immune function during influenza-associated bacterial pneumonia.
Project description:Fibroblast growth factor 21 (FGF21) is a key metabolic regulator which was recently discovered as stress-induced myokine and common denominator of muscle mitochondrial disease. However, its precise function and pathophysiological relevance remains unknown. Here we demonstrate that white adipose tissue (WAT) is the major target of muscle mitochondrial stress-induced FGF21. Strikingly, substantial browning and metabolic remodeling of subcutaneous WAT, together with the reduction of circulating triglycerides and cholesterol are fully FGF21 dependent. Unexpectedly and in contrast to prior expectations, we found a negligible role of FGF21 in muscle stress-related improved glycemic control, obesity resistance and hepatic lipid homeostasis. Furthermore, we show that the protective muscle mitohormesis and metabolic stress adaptation does not require FGF21 action. Taken together, our data imply that although FGF21 drives WAT remodeling, this effect and FGF21 as stress hormone per se may not be essential for the adaptive response under muscle mitochondrial stress conditions. Wildtype male mice and FGF21-knockout male mice, together with muscle specific UCP1-transgenic male animals, and double cross of FGF21-KO with UCP1-Tg male mice, were kept on a standardized low fat diet for 40 weeks. After sacrifice, subcutaneous white adipose tisseu (scWAT) was rapidly removed, weighed, and snap frozen in liquid nitrogen and used for RNA isolation and whole genome gene expression microarray hybridisation using Agilent arrays.