Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways in macrophage activation

BATF2 is a regulator of interferon-γ signaling in astrocytes during neuroinflammation

Astrocytic interferon (IFN)γ signaling is associated with a reduction in neuroinflammation. We have previously shown that the benefits of astrocytic IFNγ arise from a variety of mechanisms; however, downstream effectors responsible for regulating this protection are unknown. We address this by identifying a specific transcription factor that may play a key role in modulating the consequences of IFNγ signaling. RNA-sequencing of primary human astrocytes treated with IFNγ revealed basic leucine zipper ATF-like transcription factor ( BATF )2 as a highly expressed interferon-specific gene. Primarily studied in the periphery, BATF2 has been shown to exert both inflammatory and protective functions; however, its function in the central nervous system (CNS) is unknown. Here, we demonstrate that human spinal cord astrocytes upregulate BATF2 transcript and protein in an IFNγ-specific manner. Additionally, we found that BATF2 prevents overexpression of interferon regulatory factor (IRF)1 and IRF1 targets such as Caspase-1, which are known downstream pro-inflammatory mediators. We also show that Batf2 -/- mice exhibit exacerbated clinical disease severity in a murine model of CNS autoimmunity, characterized by an increase in both CNS immune cell infiltration and demyelination. Batf2 -/- mice also exhibit increased astrocyte-specific expression of IRF1 and Caspase-1, suggesting an amplified interferon response in vivo . Further, we demonstrate that BATF2 is expressed primarily in astrocytes in MS lesions and that this expression is co-localized with IRF1. Collectively, our results further support a protective role for IFNγ and implicate BATF2 as a key suppressor of overactive immune signaling in astrocytes during neuroinflammation.

Itaconate as a key player in cardiovascular immunometabolism

Cardiovascular diseases (CVDs) are the leading cause of death globally, resulting in a major health burden. Thus, an urgent need exists for exploring effective therapeutic targets to block progression of CVDs and improve patient prognoses. Immune and inflammatory responses are involved in the development of atherosclerosis, ischemic myocardial damage responses and repair, calcification, and stenosis of the aortic valve. These responses can involve both large and small blood vessels throughout the body, leading to increased blood pressure and end-organ damage. While exploring potential avenues for therapeutic intervention in CVDs, researchers have begun to focus on immune metabolism, where metabolic changes that occur in immune cells in response to exogenous or endogenous stimuli can influence immune cell effector responses and local immune signaling. Itaconate, an intermediate metabolite of the tricarboxylic acid (TCA) cycle, is related to pathophysiological processes, including cellular metabolism, oxidative stress, and inflammatory immune responses. The expression of immune response gene 1 (IRG1) is upregulated in activated macrophages, and this gene encodes an enzyme that catalyzes the production of itaconate from the TCA cycle intermediate, cis-aconitate. Itaconate and its derivatives have exerted cardioprotective effects through immune modulation in various disease models, such as ischemic heart disease, valvular heart disease, vascular disease, heart transplantation, and chemotherapy drug-induced cardiotoxicity, implying their therapeutic potential in CVDs. In this review, we delve into the associated signaling pathways through which itaconate exerts immunomodulatory effects, summarize its specific roles in CVDs, and explore emerging immunological therapeutic strategies for managing CVDs.

Nitazoxanide protects against experimental ulcerative colitis through improving intestinal barrier and inhibiting inflammation

Ulcerative colitis is a chronic disease with colonic mucosa injury. Nitazoxanide is an antiprotozoal drug in clinic. Nitazoxanide and its metabolite tizoxanide have been demonstrated to activate AMPK and inhibit inflammation, therefore, the aim of the present study is to investigate the effect of nitazoxanide on dextran sulfate sodium (DSS)-induced colitis and the underlying mechanism. Oral administration of nitazoxanide ameliorated the symptoms of mice with DSS-induced colitis, as evidenced by improving the increased disease activity index (DAI), the decreased body weight, and the shortened colon length. Oral administration of nitazoxanide ameliorated DSS-induced intestinal barrier dysfunction and reduced IL-6 and IL-17 expression in colon tissues. Mechanistically, nitazoxanide and its metabolite tizoxanide treatment activated AMPK and inhibited JAK2/STAT3 signals. Nitazoxanide and tizoxanide treatment increased caudal type homeobox 2 (CDX2) expression, increased alkaline phosphatase (ALP) activity and promoted tight junctions in Caco-2 cells. Nitazoxanide and tizoxanide treatment restored the decreased zonula occludens-1(ZO-1) and occludin protein levels induced by LPS or IL-6 in Caco-2 cells. On the other hand, nitazoxanide and tizoxanide regulated macrophage bias toward M2 polarization, as evidenced by the increased arginase-1expression in bone marrow-derived macrophages (BMDM). Nitazoxanide and tizoxanide reduced the increased IL-6, iNOS and CCL2 pro-inflammatory gene expressions and inhibited JAK2/STAT3 activation in BMDM induced by LPS. In conclusion, nitazoxanide protects against DSS-induced ulcerative colitis in mice through improving intestinal barrier and inhibiting inflammation and the underlying mechanism involves AMPK activation and JAK2/STAT3 inhibition.

Comprehensive exploration of hub genes involved in oxidative stress in rhegmatogenous retinal detachment based on bioinformatics analysis

Rhegmatogenous retinal detachment (RRD) is a type of ophthalmologic emergency, if left untreated, the blindness rate approaches 100 %. The RRD patient postoperative recovery of visual function is unsatisfactory, most notably due to photoreceptor death. We conducted to identify the key genes for oxidative stress (OS) in RRD through bioinformatics analysis and clinical validation, thus providing new ideas for the recovery of visual function in RRD patients after surgery. A gene database for RRD was obtained from the Gene Expression Omnibus (GEO) database (GSE28133). Then we screened differentially expressed OS genes (DEOSGs) from the database and assessed the critical pathways in RRD with Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Protein-protein interaction (PPI) networks and hub genes among the common DEOSGs were identified. In addition, we collected general information and vitreous fluid from 42 patients with RRD and 22 controls [11 each of epiretinal membrane (EM) and macular hole (MH)], examined the expression levels of proteins encoded by hub genes in vitreous fluid by enzyme-linked immunosorbent assay (ELISA) to further assess the relationship between the ELISA data and the clinical characteristics of patients with RRD. Ten hub genes (CCL2, ICAM1, STAT3, CD4, ITGAM, PTPRC, CCL5, IL18, TLR2, VCAM1) were finally screened out from the dataset. The ELISA results showed that, compared with the control group, patients with RRD: TLR2 and ICAM-1 were significantly elevated, and CCL2 had a tendency to be elevated, but no statistically significant; RRD patients and MH patients compared with EM patients: STAT3 and VCAM-1 were significantly elevated. We found affected eyes of RRD patients compared with healthy eyes: temporal and nasal retinal nerve fiber layer (RNFL) were significantly thickened. By correlation analysis, we found that: STAT3 was negatively correlated with ocular perfusion pressure (OPP); temporal RNFL was not only significantly positively correlated with CCL2, but also negatively correlated with Scotopic b-wave amplitude. These findings help us to further explore the mechanism of RRD development and provide new ideas for finding postoperative visual function recovery.

Enhancement of Macrophage Immunity against Chlamydial Infection by Natural Killer T Cells

Lung macrophage (LM) is vital in host defence against bacterial infections. However, the influence of other innate immune cells on its function, including the polarisation of different subpopulations, remains poorly understood. This study examined the polarisation of LM subpopulations (monocytes/undifferentiated macrophages (Mo/Mφ), interstitial macrophages (IM), and alveolar macrophages (AM)). We further assessed the effect of invariant natural killer T cells (iNKT) on LM polarisation in a protective function against Chlamydia muridarum, an obligate intracellular bacterium, and respiratory tract infection. We found a preferentially increased local Mo/Mφ and IMs with a significant shift to a type-1 macrophage (M1) phenotype and higher expression of iNOS and TNF-α. Interestingly, during the same infection, the alteration of macrophage subpopulations and the shift towards M1 was much less in iNKT KO mice. More importantly, functional testing by adoptively transferring LMs isolated from iNKT KO mice (iNKT KO-Mφ) conferred less protection than those isolated from wild-type mice (WT-Mφ). Further analyses showed significantly reduced gene expression of the JAK/STAT signalling pathway molecules in iNKT KO-Mφ. The data show an important role of iNKT in promoting LM polarisation to the M1 direction, which is functionally relevant to host defence against a human intracellular bacterial infection. The alteration of JAK/STAT signalling molecule gene expression in iNKT KO-Mφ suggests the modulating effect of iNKT is likely through the JAK/STAT pathway.

Intruders or protectors - the multifaceted role of B cells in CNS disorders

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

Mitochondrial-mediated nuclear remodeling and macrophage polarizations: A key switch from liver fibrosis to HCC progression

Liver fibrosis is a significant health burden worldwide and has emerged as the leading cause of Hepatocellular carcinoma (HCC) incidence. Mitochondria are the dynamic organelles that regulate the differentiation, survival, and polarization of macrophages. Nuclear-DNA-associated proteins, micro-RNAs, as well as macrophage polarization are essential for maintaining intracellular and extra-cellular homeostasis in the liver parenchyma. Dysregulated mitochondrial coding genes (ETS complexes I, II, III, IV, and V), non-coding RNAs (mitomiRs), and nuclear alteration lead to the production of reactive oxygen species (ROS) and inflammation which are implicated in the transition of liver fibrosis into HCC. Recent findings indicated the protecting effect of E74-like factor 3/peroxisome proliferator-activated receptor-γ (Elf-3/PPAR-γ). HDAR-y inhibits the deacetylation of PPAR-y and maintains the PPAR-y pathway. Elf-3 plays a tumor suppressive role through epithelial-mesenchymal transition-related gene and zinc finger E-box binding homeobox 2 (ZEB-2) domain. Additionally, the development of HCC includes the PI3K/Akt/mTOR and transforming Growth Factor β (TGF-β) pathway that promotes the Epithelial-mesenchymal transition (EMT) through Smad/Snail/Slug signaling cascade. In contrast, the TLR2/NOX2/autophagy axis promotes M2 polarization in HCC. Thus, a thorough understanding of the mitochondrial and nuclear reciprocal relationship related to macrophage polarization could provide new research opportunities concerning diseases with a significant impact on liver parenchyma towards developing liver fibrosis or liver cancer. Moreover, this knowledge can be used to develop new therapeutic strategies to treat liver diseases.

Roles of Macrophages and Their Interactions with Schwann Cells After Peripheral Nerve Injury

The adult peripheral nervous system has a significant ability for regeneration compared to the central nervous system. This is related to the unique neuroimmunomodulation after peripheral nerve injury (PNI). Unlike the repair of other tissues after injury, Schwann cells (SCs) respond immediately to the trauma and send out signals to precisely recruit macrophages to the injured site. Then, macrophages promote the degradation of the damaged myelin sheath by phagocytosis of local debris. At the same time, macrophages and SCs jointly secrete various cytokines to reconstruct a microenvironment suitable for nerve regeneration. This unique pathophysiological process associated with macrophages provides important targets for the repair and treatment of PNI, as well as an important reference for guiding the repair of other nerve injuries. To understand these processes more systematically, this paper describes the characteristics of macrophage activation and metabolism in PNI, discusses the underlying molecular mechanism of interaction between macrophages and SCs, and reviews the latest research progress of crosstalk regulation between macrophages and SCs. These concepts and therapeutic strategies are summarized to provide a reference for the more effective use of macrophages in the repair of PNI.

Macrophage lncRNAs in cancer development: Long-awaited therapeutic targets

In the tumor microenvironment, the interplay among macrophages, cancer cells, and endothelial cells is multifaceted. Tumor-associated macrophages (TAMs), which often exhibit an M2 phenotype, contribute to tumor growth and angiogenesis, while cancer cells and endothelial cells reciprocally influence macrophage behavior. This complex interrelationship highlights the importance of targeting these interactions for the development of novel cancer therapies aimed at disrupting tumor progression and angiogenesis. Accumulating evidence underscores the indispensable involvement of lncRNAs in shaping macrophage functionality and contributing to the development of cancer. Animal studies have further validated the therapeutic potential of manipulating macrophage lncRNA activity to ameliorate disease severity and reduce morbidity rates. This review provides a survey of our current understanding of macrophage-associated lncRNAs, with a specific emphasis on their molecular targets and their regulatory impact on cancer progression. These lncRNAs predominantly govern macrophage polarization, favoring the dominance of M2 macrophages or TAMs. Exosomes or extracellular vesicles mediate lncRNA transfer between macrophages and cancer cells, affecting cellular functions of each other. Moreover, this review presents therapeutic strategies targeting cancer-associated lncRNAs. The insights and findings presented in this review pertaining to macrophage lncRNAs can offer valuable information for the development of treatments against cancer.

An immunomodulatory role of Fc receptor γ chain independent of FcγR ligation by IgG in acute neuroinflammation triggered by MPTP intoxication

Aberrant microglial activation is a prominent feature of neuroinflammation, which is implicated in the pathogenesis of neurological disorders. Fc receptor common γ-chain (FcRγ), one of the two immunoreceptor tyrosine-based activation motif-bearing adaptor proteins, is abundantly expressed in microglia. It couples with different receptors, such as receptors for the Fc portion of IgG. In this study, we observed increased FcRγ expression along with increased IgG-binding during acute neuroinflammation triggered by MPTP intoxication, where adaptive immune responses should not be involved. Notably, FcRγ was expressed not only in the cell membrane but also in the cytoplasm in the activated microglia. FcRγ deficiency exacerbated microglial activation, pro-inflammatory factor upregulation, nigral dopaminergic neuronal loss and motor deficits, implicating a beneficial role of FcRγ in this model. Blockade of Fcγ receptor ligation by IgG in mice by Endoglycosidase S treatment, a bacterial endo-β-N-acetylglucosaminidase cleaving specifically the Asn297-linked glycan of IgG, or by using the mice deficient in mature B cells (muMT) with IgG production defects, did not show similar phenotypes to those observed in FcRγ-deficient mice, indicating that the beneficial effect mediated by FcRγ did not depend on FcγR ligation by IgG. Further, FcRγ knockout aggravated the expression and activation of STAT1 in microglia, suggesting FcRγ modulated neuroinflammation by dampening STAT1 signaling. Collectively, these results revealed that FcRγ-associated receptors could function as negative regulators of neuroinflammation and dopaminergic neurodegeneration.

Macrophage phenotype transitions in a stochastic gene-regulatory network model

Polarization is the process by which a macrophage cell commits to a phenotype based on external signal stimulation. To know how this process is affected by random fluctuations and events within a cell is of utmost importance to better understand the underlying dynamics and predict possible phenotype transitions. For this purpose, we develop a stochastic modeling approach for the macrophage polarization process. We classify phenotype states using the Robust Perron Cluster Analysis and quantify transition pathways and probabilities by applying Transition Path Theory. Depending on the model parameters, we identify four bistable and one tristable phenotype configuration. We find that bistable transitions are fast but their states less robust. In contrast, phenotype transitions in the tristable situation have a comparatively long time duration, which reflects the robustness of the states. The results indicate parallels in the overall transition behavior of macrophage cells with other heterogeneous and plastic cell types, such as cancer cells. Our approach allows for a probabilistic interpretation of macrophage phenotype transitions and biological inference on phenotype robustness. In general, the methodology can easily be adapted to other systems where random state switches are known to occur.

Identification and validation of disulfidptosis-associated molecular clusters in non-alcoholic fatty liver disease

Objective: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the world, and its pathogenesis is not fully understood. Disulfidptosis is the most recently reported form of cell death and may be associated with NAFLD progression. Our study aimed to explore the molecular clusters associated with disulfidptosis in NAFLD and to construct a predictive model. Methods: First, we analyzed the expression profile of the disulfidptosis regulators and immune characteristics in NAFLD. Using 104 NAFLD samples, we investigated molecular clusters based on differentially expressed disulfidptosis-related genes, along with the related immune cell infiltration. Cluster-specific differentially expressed genes were then identified by using the WGCNA method. We also evaluated the performance of four machine learning models before choosing the optimal machine model for diagnosis. Nomogram, calibration curves, decision curve analysis, and external datasets were used to confirm the prediction effectiveness. Finally, the expression levels of the biomarkers were assessed in a mouse model of a high-fat diet. Results: Two differentially expressed DRGs were identified between healthy and NAFLD patients. We revealed the expression profile of DRGs in NAFLD and the correlation with 22 immune cells. In NAFLD, two clusters of molecules connected to disulfidptosis were defined. Significant immunological heterogeneity was shown by immune infiltration analysis among the various clusters. A significant amount of immunological infiltration was seen in Cluster 1. Functional analysis revealed that Cluster 1 differentially expressed genes were strongly linked to energy metabolism and immune control. The highest discriminatory performance was demonstrated by the SVM model, which had a higher area under the curve, relatively small residual and root mean square errors. Nomograms, calibration curves, and decision curve analyses were used to show how accurate the prediction of NAFLD was. Further analysis revealed that the expression of three model-related genes was significantly associated with the level of multiple immune cells. In animal experiments, the expression trends of DDO, FRK and TMEM19 were consistent with the results of bioinformatics analysis. Conclusion: This study systematically elucidated the complex relationship between disulfidptosis and NAFLD and developed a promising predictive model to assess the risk of disease in patients with disulfidptosis subtypes and NAFLD.

Efficacy and Safety of Tofacitinib in Patients with Polymyalgia Rheumatica (EAST PMR): An open-label randomized controlled trial

BACKGROUND

Polymyalgia rheumatica (PMR) is a common inflammatory disease in elderly persons whose mechanism of pathogenesis has not been elucidated. Glucocorticoids are the main first-line treatments but result in numerous side effects. Therefore, there is a need to explore pathogenetic factors and identify possible glucocorticoid-sparing agents. We aimed to study the pathogenetic features of the disease and assess the efficacy and safety of Janus tyrosine kinase (JAK)-inhibitor tofacitinib in patients with PMR.

METHODS AND FINDINGS

We recruited treatment-naïve PMR patients from the First Affiliated Hospital, Zhejiang University School of Medicine, between September 2020 and September 2022. In the first cohort, we found that the gene expression patterns of peripheral blood mononuclear cells (PBMCs) in 11 patients (10 female, 1 male, age 68.0 ± 8.3) with newly diagnosed PMR were significantly different from 20 healthy controls (17 female, 3 male, age 63.7 ± 9.8) by RNA sequencing. Inflammatory response and cytokine-cytokine receptor interaction were the most notable pathways affected. We observed marked increases in expression of IL6R, IL1B, IL1R1, JAK2, TLR2, TLR4, TLR8, CCR1, CR1, S100A8, S100A12, and IL17RA, which could trigger JAK signaling. Furthermore, tofacitinib suppressed the IL-6R and JAK2 expression of CD4+T cells from patients with PMR in vitro. In the second cohort, patients with PMR were randomized and treated with tofacitinib or glucocorticoids (1/1) for 24 weeks. All PMR patients underwent clinical and laboratory examinations at 0, 4, 8, 12, 16, 20, and 24 weeks, and PMR activity disease scores (PMR-AS) were calculated. The primary endpoint was the proportion of patients with PMR-AS ≤10 at weeks 12 and 24. Secondary endpoints: PMR-AS score, c-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) at weeks 12 and 24. Thirty-nine patients with newly diagnosed PMR received tofacitinib, and 37 patients received glucocorticoid. Thirty-five patients (29 female, 6 male, age 64.4 ± 8.4) and 32 patients (23 female, 9 male, age 65.3 ± 8.7) patients completed the 24-week intervention, respectively. There were no statistically significant differences in primary or secondary outcomes. At weeks 12 and 24, all patients in both groups had PMR-AS <10. PMR-AS, CRP, and ESR were all significantly decreased in both groups. No severe adverse events were observed in either group. Study limitations included the single-center study design with a short observation period.

CONCLUSIONS

We found that JAK signaling was involved in the pathogenesis of PMR. Tofacitinib effectively treated patients with PMR as glucocorticoid does in this randomized, monocenter, open-label, controlled trial (ChiCTR2000038253).

TRIAL REGISTRATION

This investigator-initiated clinical trial (IIT) had been registered on the website (http://www.chictr.org.cn/, ChiCTR2000038253).

Regulatory mechanisms of macrophage polarization in adipose tissue

In adipose tissue, macrophages are the most abundant immune cells with high heterogeneity and plasticity. Depending on environmental cues and molecular mediators, adipose tissue macrophages (ATMs) can be polarized into pro- or anti-inflammatory cells. In the state of obesity, ATMs switch from the M2 polarized state to the M1 state, which contributes to chronic inflammation, thereby promoting the pathogenic progression of obesity and other metabolic diseases. Recent studies show that multiple ATM subpopulations cluster separately from the M1 or M2 polarized state. Various factors are related to ATM polarization, including cytokines, hormones, metabolites and transcription factors. Here, we discuss our current understanding of the potential regulatory mechanisms underlying ATM polarization induced by autocrine and paracrine factors. A better understanding of how ATMs polarize may provide new therapeutic strategies for obesity-related diseases.

Guiqi Baizhu prescription ameliorates cytarabine-induced intestinal mucositis by targeting JAK2 to inhibit M1 macrophage polarization

BACKGROUND

Intestinal mucositis (IM) is characterized by damage to the intestinal mucosa resulting from inhibition of epithelial cell division and loss of renewal capacity following anticancer chemotherapy and radiotherapy. Cytarabine (Ara-C), the main chemotherapy drug for the treatment of leukemia and lymphoma, is a frequent cause of IM. Guiqi Baizhu prescription (GQBZP) is a traditional Chinese medicine with anti-cancer and anti-inflammatory effects.

PURPOSE

To determine if GQBZP can ameliorate Ara-C induced IM and identify and characterize the pharmacologic and pharmacodynamic mechanisms.

STUDY DESIGN AND METHODS

IM was induced in mice with Ara-C and concurrently treated with orally administered GQBZP. Body weight and food intake was monitored, with HE staining to calculate ileal histomorphometric scoring and villus length/crypt depth. Immunoblotting was used to detect intestinal tissue inflammatory factors. M1 macrophages (M1) were labeled with CD86 by flow cytometry and iNOS + F4/80 by immunofluorescence. Virtual screening was used to find potentially active compounds in GQBZP that targeted JAK2. In vitro, RAW264.7 cells were skewed to M1 macrophage polarization by lipopolysaccharide (LPS) and interferon-γ (INF-γ) and treated orally with GQBZP or potential active compounds. M1 was labeled with CD86 by flow cytometry and iNOS by immunofluorescence. ELISA was used to detect inflammatory factor expression. Active compounds against JAK2, p-JAK2, STAT1 and p-STAT1 were identified by western blotting and HCS fluorescence. Molecular dynamics simulations and pharmacokinetic predictions were carried out on representative active compounds.

RESULTS

Experimental results with mice in vivo suggest that GQBZP significantly attenuated Ara-C-induced ileal damage and release of pro-inflammatory factors by inhibiting macrophage polarization to M1. Molecular docking was used to identify potentially active compounds in GQBZP that targeted JAK2, a key factor in macrophage polarization to M1. By examining the main components of each herb and applying Lipinski's rules, ten potentially active compounds were identified. In vitro experimental results suggested that all 10 compounds of GQBZP targeted JAK2 and could inhibit M1 polarization in RAW264.7 cells treated with LPS and INF-γ. Among them, acridine and senkyunolide A down-regulated the expression of JAK2 and STAT1. MD simulations revealed that acridine and senkyunolide A were stable in the active site of JAK2 and exhibited good interactions with the surrounding amino acids.

CONCLUSIONS

GQBZP can ameliorate Ara-C-induced IM by reducing macrophage polarization to M1, and acridine and senkyunolide A are representative active compounds in GQBZP that target JAK2 to inhibit M1 polarization. Targeting JAK2 to regulate M1 polarization may be a valuable therapeutic strategy for IM.

TLR7/8 agonist (R848) inhibit bovine X sperm motility via PI3K/GSK3α/β and PI3K/NFκB pathways

Sex-control technology have great economic value and is one of the hot topics in livestock research. To produce more milk, dairy farmers prefer female offspring. X/Y sperm separation is an effective method for offspring sex control. Currently, the major commercial production method for sperm separation is flow cytometry sorting in cattle. However, flow cytometry requires expensive equipment and long sorting times. So, a simple and inexpensive method for producing a higher number of dairy cows is required. In this study, R848 activates toll-like receptor 7/8 (TLR7/8), thereby separating X from Y sperm. The results showed TLR7/8 is expressed in the tail of X sperm. Immunofluorescence (IF) of testes, epididymis, and ejaculate shows that the number of TLR7⁺/8⁺ sperm cells is up to 50 %. Furthermore, TLR7/8 agonist (R848) affects mitochondrial function through the PI3K/GSK3α/β/hexokinase and PI3K/NFκB/hexokinase signalling pathways, inhibiting X sperm motility, while the motility of Y-sperm remains unchanged. The difference in sperm motility causes Y sperm (with high motility) to move to the upper layer and X-sperm (with low motility) to the lower layer allowing the separation of X and Y sperm. Based on this study, we reveal a simple and effective method for enriched X/Y sperms from cattle.

Cadmium contributes to atherosclerosis by affecting macrophage polarization

Chronic cadmium (Cd) exposure contributes to the progression of atherosclerosis, but the direct role of Cd and its mechanisms in atherosclerosis remains incompletely understood. Atherosclerosis is a chronic inflammatory disease promoting macrophage polarization to M1 phenotype and producing pro-inflammations that are vital in regulating the inflammatory response. Herein, through a case-control study, we found that Cd exposure may promote the occurrence of carotid plaque via inflammation, where interleukin-6 (IL-6) may play an important role. We also combined in vivo and in vitro experiments to explore the underlying mechanism of Cd-promoted plaque formation and the production of IL-6. With or without cadmium chloride (CdCl₂) fed ApoE^-/- mouse and treated RAW264.7 cells, we found Cd accumulated in the aortas which significantly increased the plaque area in atherosclerotic mice, macrophage accumulation, and lipid accumulation, and Cd promoted M1 phenotype macrophage polarization reflected by the increased expression of CD86 which produced tumor necrosis factor-α (TNF-α) and IL-6. However, the influences on M2 phenotype and anti-inflammatory cytokines interleukin-4 (IL-4) and interferon-γ (IFN-γ) were non-significant. Moreover, we found that JAK2/STAT3 pathway was greatly activated in the plaques and CdCl₂-treated macrophages. The inhibition of JAK2/STAT3 substantially reversed the Cd-stimulated macrophage M1 phenotype macrophage polarization and the expression of pro-inflammatory cytokines including TNF-α and IL-6. Altogether, Cd intensifies atherosclerosis by modulating macrophage polarization via JAK2/STAT3 to up-regulated the expression of IL-6.

Janus kinase/signal transducers and activator of transcription (JAK/STAT) and its role in Lung inflammatory disease

A key signaling channel for the signal transduction of several crucial cytokines implicated in sepsis is the JAK/STAT system. Once cytokines attach to the proper receptors, JAK kinases linked to them are activated and can selectively phosphorylate STATs. Activated STATs subsequently go to the nucleus, where they play a key role in the transcription of the target genes. Various biological activities use the JAK/STAT pathway, including hematopoiesis, immunological modulation, cell differentiation, and apoptosis. Inflammatory lung illnesses affect people worldwide and are a serious public health concern. Numerous common respiratory conditions, such as asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome, are strongly influenced by inflammation. Microorganism infections or the destruction or demise of host cells are the causes of inflammation and the factors that perpetuate it. This review discusses the main elements of severe lung inflammation and how the JAK/STAT signaling pathway is essential for lung inflammation.

Epigenetic regulation of macrophage polarization in wound healing

The immune microenvironment plays a critical role in regulating skin wound healing. Macrophages, the main component of infiltrating inflammatory cells, play a pivotal role in shaping the immune microenvironment in the process of skin wound healing. Macrophages comprise the classic proinflammatory M1 subtype and anti-inflammatory M2 population. In the early inflammatory phase of skin wound closure, M1-like macrophages initiate and amplify the local inflammatory response to disinfect the injured tissue. In the late tissue-repairing phase, M2 macrophages are predominant in wound tissue and limit local inflammation to promote tissue repair. The biological function of macrophages is tightly linked with epigenomic organization. Transcription factors are essential for macrophage polarization. Epigenetic modification of transcription factors determines the heterogeneity of macrophages. In contrast, transcription factors also regulate the expression of epigenetic enzymes. Both transcription factors and epigenetic enzymes form a complex network that regulates the plasticity of macrophages. Here, we describe the latest knowledge concerning the potential epigenetic mechanisms that precisely regulate the biological function of macrophages and their effects on skin wound healing.

More gain, less pain: How resistance training affects immune system functioning in multiple sclerosis patients: A review

Multiple sclerosis (MS) is characterized by a complex etiology that is mirrored by the perplexing and inconsistent treatment responses observed across different patients. Although epigenetic research has garnered rightful interest in its efforts towards demystifying and understanding aberrant responses to treatment, the interim undoubtedly requires alternative non-pharmacological approaches towards attaining more effective management strategies. Of particular interest in this review is resistance training (RT) as a non-pharmacological exercise-based interventional strategy and its potential role as a disease-modifying tool. RT has been reported across literature to positively influence numerous aspects in the quality of life (QoL) and functional capacity of MS patients, and one of the attributes of these benefits may be a shift in the immune system of these individuals. RT has also been proven to affect different immune system key players associated with MS pathology. Ultimately, this brief review aims to provide a potential yet crucial link between RT, alterations in the expression profile of the immune system, and finally an imminent improvement in the overall well-being and QoL of MS patients, suggesting that utilizing RT as an interventional exercise modality may be an effective strategy that would aid in managing such a complex and debilitating disease.

The signaling pathways and therapeutic potential of itaconate to alleviate inflammation and oxidative stress in inflammatory diseases

Endogenous small molecules are metabolic regulators of cell function. Itaconate is a key molecule that accumulates in cells when the Krebs cycle is disrupted. Itaconate is derived from cis-aconitate decarboxylation by cis-aconitate decarboxylase (ACOD1) in the mitochondrial matrix and is also known as immune-responsive gene 1 (IRG1). Studies have demonstrated that itaconate plays an important role in regulating signal transduction and posttranslational modification through its immunoregulatory activities. Itaconate is also an important bridge among metabolism, inflammation, oxidative stress, and the immune response. This review summarizes the structural characteristics and classical pathways of itaconate, its derivatives, and the compounds that release itaconate. Here, the mechanisms of itaconate action, including its transcriptional regulation of ATF3/IκBζ axis and type I IFN, its protein modification regulation of KEAP1, inflammasome, JAK1/STAT6 pathway, TET2, and TFEB, and succinate dehydrogenase and glycolytic enzyme metabolic action, are presented. Moreover, the roles of itaconate in diseases related to inflammation and oxidative stress induced by autoimmune responses, viruses, sepsis and IRI are discussed in this review. We hope that the information provided in this review will help increase the understanding of cellular immune metabolism and improve the clinical treatment of diseases related to inflammation and oxidative stress.

A balance between vector survival and virus transmission is achieved through JAK/STAT signaling inhibition by a plant virus

Viruses pose a great threat to animal and plant health worldwide, with many being dependent on insect vectors for transmission between hosts. While the virus-host arms race has been well established, how viruses and insect vectors adapt to each other remains poorly understood. Begomoviruses comprise the largest genus of plant-infecting DNA viruses and are exclusively transmitted by the whitefly Bemisia tabaci. Here, we show that the vector Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway plays an important role in mediating the adaptation between the begomovirus tomato yellow leaf curl virus (TYLCV) and whiteflies. We found that the JAK/STAT pathway in B. tabaci functions as an antiviral mechanism against TYLCV infection in whiteflies as evidenced by the increase in viral DNA and coat protein (CP) levels after inhibiting JAK/STAT signaling. Two STAT-activated effector genes, BtCD109-2 and BtCD109-3, mediate this anti-TYLCV activity. To counteract this vector immunity, TYLCV has evolved strategies that impair the whitefly JAK/STAT pathway. Infection of TYLCV is associated with a reduction of JAK/STAT pathway activity in whiteflies. Moreover, TYLCV CP binds to STAT and blocks its nuclear translocation, thus, abrogating the STAT-dependent transactivation of target genes. We further show that inhibition of the whitefly JAK/STAT pathway facilitates TYLCV transmission but reduces whitefly survival and fecundity, indicating that this JAK/STAT-dependent TYLCV-whitefly interaction plays an important role in keeping a balance between whitefly fitness and TYLCV transmission. This study reveals a mechanism of plant virus-insect vector coadaptation in relation to vector survival and virus transmission.

Spotlight on liver macrophages for halting liver disease progression and injury

INTRODUCTION

Over the past two decades, understanding of hepatic macrophage biology has provided astounding details of their role in the progression and regression of liver diseases. The hepatic macrophages constitute resident macrophages, Kupffer cells, and circulating bone marrow monocyte-derived macrophages, which play a diverse role in liver injury and repair. Imbalance in the macrophage population leads to pathological consequences and is responsible for the initiation and progression of acute and chronic liver injuries. Further, distinct populations of hepatic macrophages and their high heterogeneity make their complex role enigmatic. The unique features of distinct phenotypes of macrophages have provided novel biomarkers for defining the stages of liver diseases. The distinct mechanisms of hepatic macrophages polarization and recruitment have been at the fore front of research. In addition, the secretome of hepatic macrophages and their immune regulation has provided clinically relevant therapeutic targets.

AREAS COVERED

Herein we have highlighted the current understanding in the area of hepatic macrophages, and their role in the progression of liver injury.

EXPERT OPINION

It is essential to ascertain the physiological and pathological role of evolutionarily conserved distinct macrophage phenotypes in different liver diseases before viable approaches may see a clinical translation.

Role of exosomal non-coding RNAs from tumor cells and tumor-associated macrophages in the tumor microenvironment

Exosomes have a crucial role in intercellular communication and mediate interactions between tumor cells and tumor-associated macrophages (TAMs). Exosome-encapsulated non-coding RNAs (ncRNAs) are involved in various physiological processes. Tumor-derived exosomal ncRNAs induce M2 macrophage polarization through signaling pathway activation, signal transduction, and transcriptional and post-transcriptional regulation. Conversely, TAM-derived exosomal ncRNAs promote tumor proliferation, metastasis, angiogenesis, chemoresistance, and immunosuppression. MicroRNAs induce gene silencing by directly targeting mRNAs, whereas lncRNAs and circRNAs act as miRNA sponges to indirectly regulate protein expressions. The role of ncRNAs in tumor-host interactions is ubiquitous. Current research is increasingly focused on the tumor microenvironment. On the basis of the "cancer-immunity cycle" hypothesis, we discuss the effects of exosomal ncRNAs on immune cells to induce T cell exhaustion, overexpression of programmed cell death ligands, and create a tumor immunosuppressive microenvironment. Furthermore, we discuss potential applications and prospects of exosomal ncRNAs as clinical biomarkers and drug delivery systems.

An anti-inflammatory activation sequence governs macrophage transcriptional dynamics during tissue injury in zebrafish

Macrophages are essential for tissue repair and regeneration. Yet, the molecular programs, as well as the timing of their activation during and after tissue injury are poorly defined. Using a high spatio-temporal resolution single cell analysis of macrophages coupled with live imaging after sensory hair cell death in zebrafish, we find that the same population of macrophages transitions through a sequence of three major anti-inflammatory activation states. Macrophages first show a signature of glucocorticoid activation, then IL-10 signaling and finally the induction of oxidative phosphorylation by IL-4/Polyamine signaling. Importantly, loss-of-function of glucocorticoid and IL-10 signaling shows that each step of the sequence is independently activated. Lastly, we show that IL-10 and IL-4 signaling act synergistically to promote synaptogenesis between hair cells and efferent neurons during regeneration. Our results show that macrophages, in addition to a switch from M1 to M2, sequentially and independently transition though three anti-inflammatory pathways in vivo during tissue injury in a regenerating organ.

Dysregulated Interferon Response and Immune Hyperactivation in Severe COVID-19: Targeting STATs as a Novel Therapeutic Strategy

A disease outbreak in December 2019, caused by a novel coronavirus SARS-CoV-2, was named COVID-19. SARS-CoV-2 infects cells from the upper and lower respiratory tract system and is transmitted by inhalation or contact with infected droplets. Common clinical symptoms include fatigue, fever, and cough, but also shortness of breath and lung abnormalities. Still, some 5% of SARS-CoV-2 infections progress to severe pneumonia and acute respiratory distress syndrome (ARDS), with pulmonary edema, acute kidney injury, and/or multiple organ failure as important consequences, which can lead to death. The innate immune system recognizes viral RNAs and triggers the expression of interferons (IFN). IFNs activate anti-viral effectors and components of the adaptive immune system by activating members of the STAT and IRF families that induce the expression of IFN-stimulated genes (ISG)s. Among other coronaviruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV, common strategies have been identified to antagonize IFN signaling. This typically coincides with hyperactive inflammatory host responses known as the “cytokine storm” that mediate severe lung damage. Likewise, SARS-CoV-2 infection combines a dysregulated IFN response with excessive production of inflammatory cytokines in the lungs. This excessive inflammatory response in the lungs is associated with the local recruitment of immune cells that create a pathogenic inflammatory loop. Together, it causes severe lung pathology, including ARDS, as well as damage to other vulnerable organs, like the heart, spleen, lymph nodes, and kidney, as well as the brain. This can rapidly progress to multiple organ exhaustion and correlates with a poor prognosis in COVID-19 patients. In this review, we focus on the crucial role of different types of IFN that underlies the progression of SARS-CoV-2 infection and leads to immune cell hyper-activation in the lungs, exuberant systemic inflammation, and multiple organ damage. Consequently, to protect from systemic inflammation, it will be critical to interfere with signaling cascades activated by IFNs and other inflammatory cytokines. Targeting members of the STAT family could therefore be proposed as a novel therapeutic strategy in patients with severe COVID-19.

Role of Glycogen Synthase Kinase-3 in Interferon-γ-Mediated Immune Hepatitis

Glycogen synthase kinase-3 (GSK-3), a serine/threonine kinase, is a vital glycogen synthase regulator controlling glycogen synthesis, glucose metabolism, and insulin signaling. GSK-3 is widely expressed in different types of cells, and its abundant roles in cellular bioregulation have been speculated. Abnormal GSK-3 activation and inactivation may affect its original bioactivity. Moreover, active and inactive GSK-3 can regulate several cytosolic factors and modulate their diverse cellular functional roles. Studies in experimental liver disease models have illustrated the possible pathological role of GSK-3 in facilitating acute hepatic injury. Pharmacologically targeting GSK-3 is therefore suggested as a therapeutic strategy for liver protection. Furthermore, while the signaling transduction of GSK-3 facilitates proinflammatory interferon (IFN)-γ in vitro and in vivo, the blockade of GSK-3 can be protective, as shown by an IFN-γ-induced immune hepatitis model. In this study, we explored the possible regulation of GSK-3 and the potential relevance of GSK-3 blockade in IFN-γ-mediated immune hepatitis.

Toll signalling promotes blastema cell proliferation during cricket leg regeneration via insect macrophages

Hemimetabolous insects, such as the two-spotted cricket Gryllus bimaculatus, can recover lost tissues, in contrast to the limited regenerative abilities of human tissues. Following cricket leg amputation, the wound surface is covered by the wound epidermis, and plasmatocytes, which are insect macrophages, accumulate in the wound region. Here, we studied the function of Toll-related molecules identified by comparative RNA sequencing during leg regeneration. Of the 11 Toll genes in the Gryllus genome, expression of Toll2-1, Toll2-2 and Toll2-5 was upregulated during regeneration. RNA interference (RNAi) of Toll, Toll2-1, Toll2-2, Toll2-3 or Toll2-4 produced regeneration defects in more than 50% of crickets. RNAi of Toll2-2 led to a decrease in the ratio of S- and M-phase cells, reduced expression of JAK/STAT signalling genes, and reduced accumulation of plasmatocytes in the blastema. Depletion of plasmatocytes in crickets using clodronate also produced regeneration defects, as well as fewer proliferating cells in the regenerating legs. Plasmatocyte depletion also downregulated the expression of Toll and JAK/STAT signalling genes in the regenerating legs. These results suggest that Spz-Toll-related signalling in plasmatocytes promotes leg regeneration through blastema cell proliferation by regulating the Upd-JAK/STAT signalling pathway.

3',4',7-Trihydroxyflavone Downregulates NO Production in LPS- or IFN-γ-Activated MG6 Microglial Cells by Attenuating the JNK-STAT1 Pathway

Neuroinflammation induced by activated microglia is a key feature of neurodegenerative diseases such as Alzheimer's disease. The natural flavonoid 3',4',7-trihydroxyflavone protects nerve cells from oxidative stress-mediated apoptosis and inhibits the aggregation of amyloid β protein in vitro. However, little is known about its effects on microglial activation. In this study, we investigated the effects of 3',4',7-trihydroxyflavone on lipopolysaccharide (LPS)- or interferon-γ (IFN-γ)-induced neuroinflammatory responses in MG6 microglial cells. 3',4',7-Trihydroxyflavone inhibited LPS- or IFN-γ-mediated nitric oxide (NO) generation and the upregulation of inducible NO synthase (iNOS) in MG6 cells. 3',4',7-Trihydroxyflavone also suppressed LPS- or IFN-γ-mediated phosphorylation of signal transducer and activator of transcription 1 (STAT1), which is crucial for iNOS expression. LPS stimulation induced rapid phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and extracellular signal-regulated kinase (ERK) in MG6 cells. 3',4',7-Trihydroxyflavone significantly inhibited the LPS-mediated phosphorylation of JNK, but not that of ERK and p38 MAPK. The inhibitory effect of 3',4',7-trihydroxyflavone on NO generation was mimicked by pharmacological inhibition of the JNK signaling pathway with SP600125. Furthermore, SP600125 significantly inhibited LPS- or IFN-γ-mediated phosphorylation of STAT1 in MG6 cells. These results suggest that 3',4',7-trihydroxyflavone exerts anti-neuroinflammatory effects via inhibition of the JNK-STAT1 pathway in microglia.

The Molecular Interaction of Collagen with Cell Receptors for Biological Function

Collagen, an extracellular protein, covers the entire human body and has several important biological functions in normal physiology. Recently, collagen from non-human sources has attracted attention for therapeutic management and biomedical applications. In this regard, both land-based animals such as cow, pig, chicken, camel, and sheep, and marine-based resources such as fish, octopus, starfish, sea-cucumber, and jellyfish are widely used for collagen extraction. The extracted collagen is transformed into collagen peptides, hydrolysates, films, hydrogels, scaffolds, sponges and 3D matrix for food and biomedical applications. In addition, many strategic ideas are continuously emerging to develop innovative advanced collagen biomaterials. For this purpose, it is important to understand the fundamental perception of how collagen communicates with receptors of biological cells to trigger cell signaling pathways. Therefore, this review discloses the molecular interaction of collagen with cell receptor molecules to carry out cellular signaling in biological pathways. By understanding the actual mechanism, this review opens up several new concepts to carry out next level research in collagen biomaterials.

The role of exosomal miR-181b in the crosstalk between NSCLC cells and tumor-associated macrophages

BACKGROUND

It has been reported that tumor-associated macrophages (TAMs) participate in modulating the progression of cancer in the tumor microenvironment. However, the crosstalk between TAMs and non-small cell lung cancer (NSCLC) is still unclear.

OBJECTIVE

We investigated whether NSCLC-derived exosomes could affect TAMs, which feedback modulated progression of NSCLC.

METHODS

MiR-181b expression was measured by RT-PCR. Human THP-1 monocyte was differentiated into macrophages with phorbol myristate acetate, which were further identified by transmission electron microscopy and western blot. Macrophage M1 and M2 polarizations were detected by flow cytometry, RT-PCR and western blot. Proliferation, migration, and invasion of NSCLC cells treated with conditioned mediums were detected by EdU and Transwell assays.

RESULTS

We demonstrated that miR-181b was up-regulated in exosomes derived from NSCLC patients' serum and NSCLC cells. MiR-181b could be transferred to macrophages via exosomes in the co-culture system of macrophages and NSCLC cells, which promoted macrophage M2 polarization. Further examinations revealed that exosomes derived from NSCLC cells could enhanced macrophage M2 polarizations by regulating miR-181b/JAK2/STAT3 axis, and silencing miR-181b in NSCLC cells and JAK2 inhibitor used in macrophages could reverse the effects. Importantly, the conditioned medium of macrophages treated with NSCLC cell-derived exosomes could promote NSCLC cell proliferation, migration, and invasion. Silencing miR-181b in NSCLC cells and JAK2 inhibitor used in macrophages could block the effects.

CONCLUSIONS

All of these results indicated that exosomal miR-181b participated in the crosstalk between NSCLC cells and TAMs, providing potential therapeutic targets for NSCLC.

The mechanism of microglia-mediated immune inflammation in ischemic stroke and the role of natural botanical components in regulating microglia: A review

Ischemic stroke (IS) is one of the most fatal diseases. Neuroimmunity, inflammation, and oxidative stress play important roles in various complex mechanisms of IS. In particular, the early proinflammatory response resulting from the overactivation of resident microglia and the infiltration of circulating monocytes and macrophages in the brain after cerebral ischemia leads to secondary brain injury. Microglia are innate immune cells in the brain that constantly monitor the brain microenvironment under normal conditions. Once ischemia occurs, microglia are activated to produce dual effects of neurotoxicity and neuroprotection, and the balance of the two effects determines the fate of damaged neurons. The activation of microglia is defined as the classical activation (M1 type) or alternative activation (M2 type). M1 type microglia secrete pro-inflammatory cytokines and neurotoxic mediators to exacerbate neuronal damage, while M2 type microglia promote a repairing anti-inflammatory response. Fine regulation of M1/M2 microglial activation to minimize damage and maximize protection has important therapeutic value. This review focuses on the interaction between M1/M2 microglia and other immune cells involved in the regulation of IS phenotypic characteristics, and the mechanism of natural plant components regulating microglia after IS, providing novel candidate drugs for regulating microglial balance and IS drug development.

Macrophage Polarization and Its Role in Liver Disease

Macrophages are important immune cells in innate immunity, and have remarkable heterogeneity and polarization. Under pathological conditions, in addition to the resident macrophages, other macrophages are also recruited to the diseased tissues, and polarize to various phenotypes (mainly M1 and M2) under the stimulation of various factors in the microenvironment, thus playing different roles and functions. Liver diseases are hepatic pathological changes caused by a variety of pathogenic factors (viruses, alcohol, drugs, etc.), including acute liver injury, viral hepatitis, alcoholic liver disease, metabolic-associated fatty liver disease, liver fibrosis, and hepatocellular carcinoma. Recent studies have shown that macrophage polarization plays an important role in the initiation and development of liver diseases. However, because both macrophage polarization and the pathogenesis of liver diseases are complex, the role and mechanism of macrophage polarization in liver diseases need to be further clarified. Therefore, the origin of hepatic macrophages, and the phenotypes and mechanisms of macrophage polarization are reviewed first in this paper. It is found that macrophage polarization involves several molecular mechanisms, mainly including TLR4/NF-κB, JAK/STATs, TGF-β/Smads, PPARγ, Notch, and miRNA signaling pathways. In addition, this paper also expounds the role and mechanism of macrophage polarization in various liver diseases, which aims to provide references for further research of macrophage polarization in liver diseases, contributing to the therapeutic strategy of ameliorating liver diseases by modulating macrophage polarization.

Comprehensive analysis of prognostic immune-related genes and drug sensitivity in cervical cancer

Background

Cervical cancer (CC) is the leading cause of cancer-related death in women. A limited number of studies have investigated whether immune-prognostic features can be used to predict the prognosis of CC. This study aimed to develop an improved prognostic risk scoring model (PRSM) for CC based on immune-related genes (IRGs) to predict survival and determine the key prognostic IRGs.

Methods

We downloaded the gene expression profiles and clinical data of CC patients from the TCGA and GEO databases. The ESTIMATE algorithm was used to calculate the score for both immune and stromal cells. Differentially expressed genes (DEGs) in different subpopulations were analyzed by “Limma”. A weighted gene co-expression network analysis (WGCNA) was used to establish a DEG co-expression module related to the immune score. Immune-related gene pairs (IRGPs) were constructed, and univariate- and Lasso-Cox regression analyses were used to analyze prognosis and establish a PRSM. A log-rank test was used to verify the accuracy and consistency of the scoring model. Identification of the predicted key IRG was ensured by the application of functional enrichment, DisNor, protein–protein interactions (PPIs) and heatmap. Finally, we extracted the key prognostic immune-related genes from the gene expression data, validated the key genes by immunohistochemistry and analyzed the correlation between their expression and drug sensitivity.

Results

A new PRSM was developed based on 22 IRGPs. The prognosis of the low-risk group in the model group (P < 0.001) and validation group (P = 0.039) was significantly better than that in the high-risk group. Furthermore, M1 and M2 macrophages were highly expressed in the low-risk group. Retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) and the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway were significantly enriched in the low-risk group. Three representative genes (CD80, CD28, and LCP2) were markers of CC prognosis. CD80 and CD28 may more prominent represent important indicators to improve patient prognosis. These key genes was positively correlated with drug sensitivity. Finally, we found that differences in the sensitivity to JNK inhibitors could be distinguished based on the use and risk grouping of this PRSM.

Conclusions

The prognostic model based on the IRGs and key genes have potential clinical significance for predicting the prognosis of CC patients, providing a foundation for clinical prognosis judgment and individualized treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02333-9.

Trem1 Induces Periodontal Inflammation via Regulating M1 Polarization

Periodontitis is a chronic inflammatory condition characterized by destruction of nonmineralized and mineralized connective tissues. This study evaluated the role of Trem1 (triggering receptors expressed on myeloid cells 1) in periodontitis by influencing polarization of M1 macrophages through the STAT3/HIF-1α signaling pathway. Trem1 was significantly upregulated in the gingival tissues of patients with periodontitis, as identified by high-throughput RNA sequencing, and positively correlated with levels of M1 macrophage-associated genes. The results of flow cytometry, Western blotting, and reverse transcription quantitative polymerase chain reaction showed that knockdown of Trem1 in RAW 264.7 cells decreased polarization of M1 macrophages and increased polarization of M2 macrophages, while overexpression of Trem1 exerted an opposite effect. Furthermore, a mouse model of Trem1 knockout periodontitis exhibited limited infiltration of macrophages and decreased expression levels of M1 macrophage-associated genes in periodontitis lesions and bone marrow-derived macrophages. Importantly, we found that Trem1 could regulate polarization of M1 macrophages through STAT3/HIF-1α signaling as evidenced by RNA sequencing. Moreover, inhibition of Trem1 and HIF-1α could suppress the expression level of proinflammatory cytokine (interleukin 1β) and upregulate the expression level of anti-inflammatory cytokine (interleukin 10) in periodontitis. Collectively, we identified that the Trem1/STAT3/HIF-1α axis could regulate polarization of M1 macrophages and is a potential candidate in the treatment of periodontitis.

The triumvirate of NF-κB, inflammation and cytokine storm in COVID-19

The coronavirus disease (COVID-19) has once again reminded us of the significance of host immune response and consequential havocs of the immune dysregulation. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) inflicts severe complications to the infected host, including cough, dyspnoea, fever, septic shock, acute respiratory distress syndrome (ARDs), and multiple organ failure. These manifestations are the consequence of the dysregulated immune system, which gives rise to excessive and unattended production of pro-inflammatory mediators. Elevated circulatory cytokine and chemokine levels are accompanied by spontaneous haemorrhage, thrombocytopenia and systemic inflammation, which are the cardinal features of life-threatening cytokine storm syndrome in advanced COVID-19 diseases. Coronavirus hijacked NF-kappa B (NF-κB) is responsible for upregulating the expressions of inflammatory cytokine, chemokine, alarmins and inducible enzymes, which paves the pathway for cytokine storm. Given the scenario, the systemic approach of simultaneous inhibition of NF-κB offers an attractive therapeutic intervention. Targeted therapies with proteasome inhibitor (VL-01, bortezomib, carfilzomib and ixazomib), bruton tyrosine kinase inhibitor (acalabrutinib), nucleotide analogue (remdesivir), TNF-α monoclonal antibodies (infliximab and adalimumab), N-acetylcysteine and corticosteroids (dexamethasone), focusing the NF-κB inhibition have demonstrated effectiveness in terms of the significant decrease in morbidity and mortality in severe COVID-19 patients. Hence, this review highlights the activation, signal transduction and cross-talk of NF-κB with regard to cytokine storm in COVID-19. Moreover, the development of therapeutic strategies based on NF-κB inhibition are also discussed herein.

Research Progress in Anti-Inflammatory Bioactive Substances Derived from Marine Microorganisms, Sponges, Algae, and Corals

Inflammation is the body's defense reaction in response to stimulations and is the basis of various physiological and pathological processes. However, chronic inflammation is undesirable and closely related to the occurrence and development of diseases. The ocean gives birth to unique and diverse bioactive substances, which have gained special attention and been a focus for anti-inflammatory drug development. So far, numerous promising bioactive substances have been obtained from various marine organisms such as marine bacteria and fungi, sponges, algae, and coral. This review covers 71 bioactive substances described during 2015-2020, including the structures (65 of which), species sources, evaluation models and anti-inflammatory activities of these substances. This review aims to provide some reference for the research progress of marine-organism-derived anti-inflammatory metabolites and give more research impetus for their conversion to novel anti-inflammatory drugs.

The network interplay of interferon and Toll-like receptor signaling pathways in the anti-Candida immune response

Fungal infections represent a major global health problem affecting over a billion people that kills more than 1.5 million annually. In this study, we employed an integrative approach to reveal the landscape of the human immune responses to Candida spp. through meta-analysis of microarray, bulk, and single-cell RNA sequencing (scRNA-seq) data for the blood transcriptome. We identified across these different studies a consistent interconnected network interplay of signaling molecules involved in both Toll-like receptor (TLR) and interferon (IFN) signaling cascades that is activated in response to different Candida species (C. albicans, C. auris, C. glabrata, C. parapsilosis, and C. tropicalis). Among these molecules are several types I IFN, indicating an overlap with antiviral immune responses. scRNA-seq data confirmed that genes commonly identified by the three transcriptomic methods show cell type-specific expression patterns in various innate and adaptive immune cells. These findings shed new light on the anti-Candida immune response, providing putative molecular pathways for therapeutic intervention.

Curcumin Alleviated Dextran Sulfate Sodium-Induced Colitis by Regulating M1/M2 Macrophage Polarization and TLRs Signaling Pathway

Curcumin has shown good efficacy in mice with experimental colitis and in patients with ulcerative colitis, but the mechanism of action through the regulation of M1/M2 macrophage polarization has not been elaborated. The ulcerative colitis was modeled by dextran sulfate sodium; colitis mice were orally administrated with curcumin (10 mg/kg/day) or 5-ASA (300 mg/kg/day) for 14 consecutive days. After curcumin treatment, the body weight, colon weight and length, colonic weight index, and histopathological damage in colitis mice were effectively improved. The concentrations of proinflammatory cytokines IL-1β, IL-6, and CCL-2 in the colonic tissues of colitis mice decreased significantly, while anti-inflammatory cytokines IL-33 and IL-10 increased significantly. Importantly, macrophage activation was suppressed and M1/M2 macrophage polarization was regulated in colitis mice, and the percentage of CD11b⁺F4/80⁺ and CD11b⁺F4/80⁺TIM-1⁺ and CD11b⁺F4/80⁺iNOS⁺ decreased significantly and CD11b⁺F4/80⁺CD206⁺ and CD11b⁺F4/80⁺CD163⁺ increased significantly. Additionally, curcumin significantly downregulated CD11b⁺F4/80⁺TLR4⁺ macrophages and the protein levels of TLR2, TLR4, MyD88, NF-κBp65, p38MAPK, and AP-1 in colitis mice. Our study suggested that curcumin exerted therapeutic effects in colitis mice by regulating the balance of M1/M2 macrophage polarization and TLRs signaling pathway.

A Shotgun Proteomic Platform for a Global Mapping of Lymphoblastoid Cells to Gain Insight into Nasu-Hakola Disease

Nasu-Hakola Disease (NHD) is a recessively inherited systemic leukodystrophy disorder characterized by a combination of frontotemporal presenile dementia and lytic bone lesions. NHD is known to be genetically related to a structural defect of TREM2 and DAP12, two genes that encode for different subunits of the membrane receptor signaling complex expressed by microglia and osteoclast cells. Because of its rarity, molecular or proteomic studies on this disorder are absent or scarce, only case reports based on neuropsychological and genetic tests being reported. In light of this, the aim of this paper is to provide evidence on the potential of a label-free proteomic platform based on the Multidimensional Protein Identification Technology (MudPIT), combined with in-house software and on-line bioinformatics tools, to characterize the protein expression trends and the most involved pathways in NHD. The application of this approach on the Lymphoblastoid cells from a family composed of individuals affected by NHD, healthy carriers and control subjects allowed for the identification of about 3000 distinct proteins within the three analyzed groups, among which proteins anomalous to each category were identified. Of note, several differentially expressed proteins were associated with neurodegenerative processes. Moreover, the protein networks highlighted some molecular pathways that may be involved in the onset or progression of this rare frontotemporal disorder. Therefore, this fully automated MudPIT platform which allowed, for the first time, the generation of the whole protein profile of Lymphoblastoid cells from Nasu-Hakola subjects, could be a valid approach for the investigation of similar neurodegenerative diseases.

Interfering with interferons: targeting the JAK-STAT pathway in complications of systemic juvenile idiopathic arthritis (SJIA)

Systemic JIA (SJIA) is distinguished from other forms of JIA by the prevalence of the severe, life-threatening complications macrophage activation syndrome (SJIA-MAS) and lung disease (SJIA-LD). Alternative therapeutics are urgently needed, as disease pathogenesis diverges from what is observed in SJIA, and currently available biologics are insufficient. SJIA-MAS, defined by a cytokine storm and dysregulated proliferation of T-lymphocytes, and SJIA-LD which presents with lymphocytic interstitial inflammation and pulmonary alveolar proteinosis, are both thought to be driven by IFNs, in particular the type II IFN-γ. Involvement of IFNs and a possible crosstalk of type I IFNs with existing biologics indicate a distinct role for the JAK-STAT signalling pathway in the pathogenesis of SJIA-MAS and SJIA-LD. Here, we review this role of JAK-STATs and IFNs in SJIA complications and discuss how new insights of ongoing research are shaping future therapeutic advances in the form of JAK inhibitors and antibodies targeting IFNs.

Modulating Repolarization of Tumor-Associated Macrophages with Targeted Therapeutic Nanoparticles as a Potential Strategy for Cancer Therapy

There are always some components in the tumor microenvironment (TME), such as tumor-associated macrophages (TAMs), that help tumor cells escape the body's immune surveillance. Therefore, this situation can lead to tumor growth, progression, and metastasis, resulting in low response rates for cancer therapy. Macrophages play an important role with strong plasticity and functional diversity. Facing different microenvironmental stimulations, macrophages undergo a dynamic change in phenotype and function into two major macrophage subpopulations, namely classical activation/inflammation (M1) and alternative activation/regeneration (M2) type. Through various signaling pathways, macrophages polarize into complex groups, which can perform different immune functions. In this review, we emphasize the use of nanopreparations for macrophage related immunotherapy based on the pathological knowledge of TAMs phenotype. These macrophages targeted nanoparticles re-edit and re-educate macrophages by attenuating M2 macrophages and reducing aggregation to the TME, thereby relieving or alleviating immunosuppression. Among them, we describe in detail the cellular mechanisms and regulators of several major signaling pathways involved in the plasticity and polarization functions of macrophages. The advantages and challenges of those nanotherapeutics for these pathways have been elucidated, providing the basis and insights for the diagnosis and treatment strategies of various diseases centered on macrophages.

Assessment of Expression of SOCS Genes in Acquired Immune-Mediated Polyneuropathies

Acquired immune-mediated polyneuropathies are classified to some subtypes among them are acute and chronic inflammatory demyelinating polyradiculoneuropathies (AIDP and CIDP). These two conditions share some common signs and underlying mechanisms. Based on the roles of Suppressor of cytokine signaling (SOCS) genes in the modulation of immune system reactions, these genes might be involved in the pathogenesis of these conditions. We evaluated expression of SOCS1-3 and SOCS5 genes in the leukocytes of 32 cases of CIDP, 19 cases of AIDP and 40 age- and sex-matched controls using real time PCR method. The Bayesian regression model was used to estimate differences in mean values of genes expressions between cases and control group. Expression levels of SOCS1 and SOCS2 were significantly lower in male patients compared with controls. This sex-specific pattern was also observed for SOCS3 down-regulation. Based on the area under curve values in Receiver Operating Characteristics (ROC) curve, diagnostic powers of SOCS1, SOCS2, SOCS3 and SOCS5 genes in the mentioned disorder were 0.61, 0.73, 0.68 and 0.58, respectively. Expression of none of genes was correlated with age of enrolled cases. The current study shows evidences for participation of SOCS genes in the pathophysiology of acquired immune-mediated polyneuropathies.

Radiosensitivity index emerges as a potential biomarker for combined radiotherapy and immunotherapy

In the era of immunotherapy, there lacks of a reliable genomic predictor to identify optimal patient populations in combined radiotherapy and immunotherapy (CRI). The purpose of this study is to investigate whether genomic scores defining radiosensitivity are associated with immune response. Genomic data from Merged Microarray-Acquired dataset (MMD) were established and the Cancer Genome Atlas (TCGA) were obtained. Based on rank-based regression model including 10 genes, radiosensitivity index (RSI) was calculated. A total of 12832 primary tumours across 11 major cancer types were analysed for the association with DNA repair, cellular stemness, macrophage polarisation, and immune subtypes. Additional 585 metastatic tissues were extracted from MET500. RSI was stratified into RSI-Low and RSI-High by a cutpoint of 0.46. Proteomic differential analysis was used to identify significant proteins according to RSI categories. Gene Set Variance Analysis (GSVA) was applied to measure the genomic pathway activity (18 genes for T-cell inflamed activity). Kaplan-Meier analysis was performed for survival analysis. RSI was significantly associated with homologous DNA repair, cancer stemness and immune-related molecular features. Lower RSI was associated with higher fraction of M1 macrophage. Differential proteomic analysis identified significantly higher TAP2 expression in RSI-Low colorectal tumours. In the TCGA cohort, dominant interferon-γ (IFN-γ) response was characterised by low RSI and predicted better response to programmed cell death 1 (PD-1) blockade. In conclusion, in addition to radiation response, our study identified RSI to be associated with various immune-related features and predicted response to PD-1 blockade, thus, highlighting its potential as a candidate biomarker for CRI.

Macrophages activated by akermanite/alginate composite hydrogel stimulate migration of bone marrow-derived mesenchymal stem cells

Akermanite (Aker) has been widely used for bone regeneration through regulating osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). Previously, we developed an injectable Aker/sodium alginate (Aker/SA) hydrogel to facilitate bone regeneration. However, the effect of this injectable hydrogel on the in vivo response, particularly the inflammatory response, has not been fully understood. Here, to elucidate the response following the implantable of Aker/SA hydrogel, we investigated the interaction among Aker/SA hydrogel, inflammatory cells and cells involved in bone regeneration (BMSCs). Specifically, we cultured macrophages (RAW 264.7 cell line) with the extract liquid of Aker/SA and assessed their phenotypic changes. Subsequently, BMSCs (2*10^5 cells per 24 well) were cultured with different conditioned media including that of Aker/SA hydrogel-activated macrophages to investigate their effect on cell migration. Finally, Aker/SA hydrogel was injected subcutaneously (1*10^6 cells per ml) in rat to verify its effect in vivo. The in vitro results indicated that Aker/SA hydrogel activated macrophages towards M2 phenotype and stimulated macrophages to express anti-inflammatory factors. In addition, the conditioned medium collected from Aker-activated macrophages could accelerate the migration of BMSCs in 24h. Consistent with the in vitro results, when the Aker/SA hydrogel was injected subcutaneously, more M2 macrophages could be observed than when the SA solution was injected after 7 days. Besides, when BMSCs were delivered via subcutaneous injection, more BMSCs were recruited by the Aker/SA hydrogel than the SA solution. All these results suggest that the Aker/SA hydrogel can modulate the immune environment at the implantation site and subsequently recruit BMSCs, which can be one of the mechanisms through which the Aker/SA hydrogel accelerates new bone formation.

Network Analysis Reveals a Distinct Axis of Macrophage Activation in Response to Conflicting Inflammatory Cues

Macrophages are subject to a wide range of cytokine and pathogen signals in vivo, which contribute to differential activation and modulation of inflammation. Understanding the response to multiple, often-conflicting cues that macrophages experience requires a network perspective. In this study, we integrate data from literature curation and mRNA expression profiles obtained from wild type C57/BL6J mice macrophages to develop a large-scale computational model of the macrophage signaling network. In response to stimulation across all pairs of nine cytokine inputs, the model predicted activation along the classic M1-M2 polarization axis but also a second axis of macrophage activation that distinguishes unstimulated macrophages from a mixed phenotype induced by conflicting cues. Along this second axis, combinations of conflicting stimuli, IL-4 with LPS, IFN-γ, IFN-β, or TNF-α, produced mutual inhibition of several signaling pathways, e.g., NF-κB and STAT6, but also mutual activation of the PI3K signaling module. In response to combined IFN-γ and IL-4, the model predicted genes whose expression was mutually inhibited, e.g., iNOS or Nos2 and Arg1, or mutually enhanced, e.g., Il4rα and Socs1, validated by independent experimental data. Knockdown simulations further predicted network mechanisms underlying functional cross-talk, such as mutual STAT3/STAT6-mediated enhancement of Il4rα expression. In summary, the computational model predicts that network cross-talk mediates a broadened spectrum of macrophage activation in response to mixed pro- and anti-inflammatory cytokine cues, making it useful for modeling in vivo scenarios.