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Current Issues in Molecular Biology Jun 2024Nonalcoholic steatohepatitis (NASH) is characterized by severe inflammation and fibrosis due to an excessive accumulation of triglycerides (TGs) in the liver with a...
Nonalcoholic steatohepatitis (NASH) is characterized by severe inflammation and fibrosis due to an excessive accumulation of triglycerides (TGs) in the liver with a dysregulated de novo lipogenesis (DNL) pathway. In this study, we aimed to evaluate the effectiveness of YC-1102, an extract obtained from the roots of , as a nutritional supplement in a diet-induced NASH mouse model. C57BL/6 wild-type mice were fed a fructose, palmitate, and cholesterol (FPC)-containing diet for 16 weeks to induce experimental NASH. A daily oral gavage of YC-1102 and obetichoic acid (OCA) was conducted for 9 weeks. After sacrifice, disease parameters related to hepatic lipids, inflammation, and fibrosis were evaluated. The treatment with YC-1102 significantly decreased the liver/body weight ratio, epididymal fat weight, and plasma ALT and AST levels, which are indicators of NASH injuries. YC-1102 attenuated hepatic lipid accumulation by inhibiting the transcription of DNL genes in the livers exhibiting NASH. Additionally, we found that YC-1102 blocked the development of hepatic inflammation and fibrosis by directly disturbing macrophage activation, resulting in an amelioration of hepatic fibrosis. Our findings suggest that YC-1102 could ameliorate NASH progression by inhibiting uncontrolled DNL and inflammation.
PubMed: 38921022
DOI: 10.3390/cimb46060351 -
Cells Jun 2024Multiple sclerosis (MS) is a clinically heterogeneous disease underpinned by inflammatory, demyelinating and neurodegenerative processes, the extent of which varies...
BACKGROUND
Multiple sclerosis (MS) is a clinically heterogeneous disease underpinned by inflammatory, demyelinating and neurodegenerative processes, the extent of which varies between individuals and over the course of the disease. Recognising the clinicopathological features that most strongly associate with disease outcomes will inform future efforts at patient phenotyping.
AIMS
We used a digital pathology workflow, involving high-resolution image acquisition of immunostained slides and opensource software for quantification, to investigate the relationship between clinical and neuropathological features in an autopsy cohort of progressive MS.
METHODS
Sequential sections of frontal, cingulate and occipital cortex, thalamus, brain stem (pons) and cerebellum including dentate nucleus (n = 35 progressive MS, females = 28, males = 7; age died = 53.5 years; range 38-98 years) were immunostained for myelin (anti-MOG), neurons (anti-HuC/D) and microglia/macrophages (anti-HLA). The extent of demyelination, neurodegeneration, the presence of active and/or chronic active lesions and quantification of brain and leptomeningeal inflammation was captured by digital pathology.
RESULTS
Digital analysis of tissue sections revealed the variable extent of pathology that characterises progressive MS. Microglia/macrophage activation, if found at a higher level in a single block, was typically elevated across all sampled blocks. Compartmentalised (perivascular/leptomeningeal) inflammation was associated with age-related measures of disease severity and an earlier death.
CONCLUSION
Digital pathology identified prognostically important clinicopathological correlations in MS. This methodology can be used to prioritise the principal pathological processes that need to be captured by future MS biomarkers.
Topics: Humans; Middle Aged; Female; Male; Multiple Sclerosis; Aged; Adult; Biomarkers; Aged, 80 and over; Inflammation; Brain; Microglia; Macrophages
PubMed: 38920650
DOI: 10.3390/cells13121020 -
Rheumatology Advances in Practice 2024
PubMed: 38919835
DOI: 10.1093/rap/rkae078 -
Frontiers in Immunology 2024Inflammatory cytokines play key pathogenic roles in liver fibrosis. IL-15 is a proinflammatory cytokine produced by myeloid cells. IL-15 promotes pathogenesis of several...
BACKGROUND
Inflammatory cytokines play key pathogenic roles in liver fibrosis. IL-15 is a proinflammatory cytokine produced by myeloid cells. IL-15 promotes pathogenesis of several chronic inflammatory diseases. However, increased liver fibrosis has been reported in mice lacking IL-15 receptor alpha chain (IL-15Rα), suggesting an anti-fibrogenic role for IL-15. As myeloid cells are key players in liver fibrosis and IL-15 signaling can occur independently of IL-15Rα, we investigated the requirement of IL-15 and IL-15Rα in liver fibrosis.
METHODS
We induced liver fibrosis in , and wildtype C57BL/6 mice by the administration of carbon tetrachloride (CCl). Liver fibrosis was evaluated by Sirius red and Mason's trichrome staining and α-smooth muscle acting immunostaining of myofibroblasts. Gene expression of collagens, matrix modifying enzymes, cytokines and chemokines was quantified by RT-qPCR. The phenotype and the numbers of intrahepatic lymphoid and myeloid cell subsets were evaluated by flow cytometry.
RESULTS
Both and mice developed markedly reduced liver fibrosis compared to wildtype control mice, as revealed by reduced collagen deposition and myofibroblast content. mice showed further reduction in collagen deposition compared to mice. However, and genes were similarly induced in the fibrotic livers of wildtype, and mice, although notable variations were observed in the expression of matrix remodeling enzymes and chemokines. As expected, and mice showed markedly reduced numbers of NK cells compared to wildtype mice. They also showed markedly less staining of CD45 immune cells and CD68 macrophages, and significantly reduced inflammatory cell infiltration into the liver, with fewer pro-inflammatory and anti-inflammatory monocyte subsets compared to wildtype mice.
CONCLUSION
Our findings indicate that IL-15 exerts its profibrogenic role in the liver by promoting macrophage activation and that this requires trans-presentation of IL-15 by IL-15Rα.
Topics: Animals; Interleukin-15; Mice; Carbon Tetrachloride; Interleukin-15 Receptor alpha Subunit; Liver Cirrhosis; Mice, Knockout; Mice, Inbred C57BL; Disease Models, Animal; Male; Liver; Cytokines; Receptors, Interleukin-15
PubMed: 38919611
DOI: 10.3389/fimmu.2024.1404891 -
Frontiers in Immunology 2024Therapeutic antibodies have become a major strategy to treat oncologic diseases. For chronic lymphocytic leukemia, antibodies against CD20 are used to target and elicit...
INTRODUCTION
Therapeutic antibodies have become a major strategy to treat oncologic diseases. For chronic lymphocytic leukemia, antibodies against CD20 are used to target and elicit cytotoxic responses against malignant B cells. However, efficacy is often compromised due to a suppressive microenvironment that interferes with cellular immune responses. To overcome this suppression, agonists of pattern recognition receptors have been studied which promote direct cytotoxicity or elicit anti-tumoral immune responses. NOD2 is an intracellular pattern recognition receptor that participates in the detection of peptidoglycan, a key component of bacterial cell walls. This detection then mediates the activation of multiple signaling pathways in myeloid cells. Although several NOD2 agonists are being used worldwide, the potential benefit of these agents in the context of antibody therapy has not been explored.
METHODS
Primary cells from healthy-donor volunteers (PBMCs, monocytes) or CLL patients (monocytes) were treated with versus without the NOD2 agonist L18-MDP, then antibody-mediated responses were assessed. In vivo, the Eµ-TCL1 mouse model of CLL was used to test the effects of L18-MDP treatment alone and in combination with anti-CD20 antibody.
RESULTS
Treatment of peripheral blood mononuclear cells with L18-MDP led to activation of monocytes from both healthy donors and CLL patients. In addition, there was an upregulation of activating FcγR in monocytes and a subsequent increase in antibody-mediated phagocytosis. This effect required the NF-κB and p38 signaling pathways. Treatment with L18-MDP plus anti-CD20 antibody in the Eµ-TCL model of CLL led to a significant reduction of CLL load, as well as to phenotypic changes in splenic monocytes and macrophages.
CONCLUSIONS
Taken together, these results suggest that NOD2 agonists help overturn the suppression of myeloid cells, and may improve the efficacy of antibody therapy for CLL.
Topics: Nod2 Signaling Adaptor Protein; Animals; Humans; Receptors, IgG; Mice; Macrophages; Leukemia, Lymphocytic, Chronic, B-Cell; Acetylmuramyl-Alanyl-Isoglutamine; Female; Mice, Inbred C57BL; Signal Transduction; Phagocytosis; Rituximab
PubMed: 38919608
DOI: 10.3389/fimmu.2024.1409333 -
Journal of Neuroinflammation Jun 2024The SARS-CoV-2 virus activates maternal and placental immune responses. Such activation in the setting of other infections during pregnancy is known to impact fetal...
BACKGROUND
The SARS-CoV-2 virus activates maternal and placental immune responses. Such activation in the setting of other infections during pregnancy is known to impact fetal brain development. The effects of maternal immune activation on neurodevelopment are mediated at least in part by fetal brain microglia. However, microglia are inaccessible for direct analysis, and there are no validated non-invasive surrogate models to evaluate in utero microglial priming and function. We have previously demonstrated shared transcriptional programs between microglia and Hofbauer cells (HBCs, or fetal placental macrophages) in mouse models.
METHODS AND RESULTS
We assessed the impact of maternal SARS-CoV-2 on HBCs isolated from 24 term placentas (N = 10 SARS-CoV-2 positive cases, 14 negative controls). Using single-cell RNA-sequencing, we demonstrated that HBC subpopulations exhibit distinct cellular programs, with specific subpopulations differentially impacted by SARS-CoV-2. Assessment of differentially expressed genes implied impaired phagocytosis, a key function of both HBCs and microglia, in some subclusters. Leveraging previously validated models of microglial synaptic pruning, we showed that HBCs isolated from placentas of SARS-CoV-2 positive pregnancies can be transdifferentiated into microglia-like cells (HBC-iMGs), with impaired synaptic pruning behavior compared to HBC models from negative controls.
CONCLUSION
These findings suggest that HBCs isolated at birth can be used to create personalized cellular models of offspring microglial programming.
Topics: Female; Pregnancy; Microglia; Humans; Placenta; COVID-19; Macrophages; Pregnancy Complications, Infectious; SARS-CoV-2; Fetus; Adult; Brain; Mice; Animals
PubMed: 38918792
DOI: 10.1186/s12974-024-03157-w -
Signal Transduction and Targeted Therapy Jun 2024
Topics: Tuberculosis; Macrophages; Humans; Nanoparticles; Cell Membrane; Animals; Mycobacterium tuberculosis; Macrophage Activation; Mice
PubMed: 38918362
DOI: 10.1038/s41392-024-01855-8 -
Biomedicine & Pharmacotherapy =... Jun 2024Non-alcoholic steatohepatitis (NASH) and liver fibrosis are progressive conditions associated with non-alcoholic fatty liver disease (NAFLD), characterized by hepatocyte...
BACKGROUND
Non-alcoholic steatohepatitis (NASH) and liver fibrosis are progressive conditions associated with non-alcoholic fatty liver disease (NAFLD), characterized by hepatocyte pyroptosis and hepatic stellate cell (HSC) activation. Gentiopicroside (GPS) has emerged as a potential treatment for NASH, yet its underlying mechanism remains unclear.
AIM
To confirm that GPS can improve NASH and liver fibrosis by blocking the NLRP3 signaling pathway STUDY DESIGN: Initially, different animal models were used to study the effects and mechanisms of GPS on NASH and fibrosis. Subsequent in vitro experiments utilized co-cultures and other techniques to delve deeper into its mechanism, followed by validation of the findings in mouse liver tissues.
METHODS
C57BL/6 mice were fed high-fat, high-cholesterol (HFHC), or methionine-choline-deficient (MCD) diets to induce NASH and fibrosis. RAW264.7 cells and born marrow bone marrow-derived macrophages (BMDMs) were stimulated with LPS and ATP to induce inflammation, then co-cultured with primary hepatocytes and HSCs, treated with GPS, and its efficacy and mechanism were analyzed.
RESULTS
In vivo, GPS alleviated NASH and liver fibrosis by inhibiting the NLRP3 pathway. In vitro, GPS attenuated inflammation induced by BMDMs by inhibiting TLR4 and NLRP3 signaling pathways, and Co-culture studies suggested that GPS reduced hepatocyte pyroptosis and HSC activation, which was also confirmed in liver tissues CONCLUSION: GPS improves NASH and liver fibrosis by inhibiting the TLR4 and NLRP3 signaling pathways. The specific mechanism may be related to the suppression of macrophage-mediated inflammatory responses, thereby reducing hepatocyte pyroptosis and HSC activation.
PubMed: 38917754
DOI: 10.1016/j.biopha.2024.116952 -
BioRxiv : the Preprint Server For... Jun 2024Macrophages exhibit marked phenotypic heterogeneity within and across disease states, with lipid metabolic reprogramming contributing to macrophage activation and...
Macrophages exhibit marked phenotypic heterogeneity within and across disease states, with lipid metabolic reprogramming contributing to macrophage activation and heterogeneity. Chronic inflammation has been observed in human benign prostatic hyperplasia (BPH) tissues, however macrophage activation states and their contributions to this hyperplastic disease have not been defined. We postulated that a shift in macrophage phenotypes with increasing prostate size could involve metabolic alterations resulting in prostatic epithelial or stromal hyperplasia. Single-cell RNA-seq of CD45 transition zone leukocytes from 10 large (>90 grams) and 10 small (<40 grams) human prostates was conducted. Macrophage subpopulations were defined using marker genes. BPH macrophages do not distinctly categorize into M1 and M2 phenotypes. Instead, macrophages with neither polarization signature preferentially accumulate in large versus small prostates. Specifically, macrophage subpopulations with altered lipid metabolism pathways, demarcated by and expression, significantly accumulate with increased prostate volume. and macrophage abundance positively correlates with patient body mass index and urinary symptom scores. TREM2 macrophages have significantly higher neutral lipid than TREM2 macrophages from BPH tissues. Lipid-rich macrophages were observed to localize within the stroma in BPH tissues. studies indicate that lipid-loaded macrophages increase prostate epithelial and stromal cell proliferation compared to control macrophages. These data define two new BPH immune subpopulations, TREM2 and MARCO macrophages, and suggest that lipid-rich macrophages may exacerbate lower urinary tract symptoms in patients with large prostates. Further investigation is needed to evaluate the therapeutic benefit of targeting these cells in BPH.
PubMed: 38915654
DOI: 10.1101/2024.06.07.597992 -
BioRxiv : the Preprint Server For... Jun 2024Macrophages exhibit a spectrum of behaviors upon activation and are generally classified as one of two types: inflammatory (M1) or anti-inflammatory (M2). Tracking these...
Macrophages exhibit a spectrum of behaviors upon activation and are generally classified as one of two types: inflammatory (M1) or anti-inflammatory (M2). Tracking these phenotypes in living cells can provide insight into immune function, but remains a challenging pursuit. Existing methods are mostly limited to static readouts or difficult to employ for multiplexed imaging in complex 3D environments while maintaining cellular resolution. We aimed to fill this void using bioluminescent technologies. Here we report genetically engineered luciferase reporters for long-term monitoring of macrophage polarization via spectral phasor analysis. M1- and M2- specific promoters were used to drive the expression of bioluminescent enzymes in macrophage cell lines. The readouts were multiplexed and discernable in both 2D and 3D formats with single cell resolution in living samples. Collectively, this work expands the toolbox of methods for monitoring macrophage polarization and provides a blueprint for monitoring other multifaceted networks in heterogeneous environments.
PubMed: 38915606
DOI: 10.1101/2024.06.10.598305