Zanubrutinib ameliorates lipopolysaccharide-induced acute lung injury via regulating macrophage polarization

Zanubrutinib ameliorates experimental idiopathic inflammatory myopathy-associated interstitial lung disease by BTK/NF-κB signaling pathway

Idiopathic inflammatory myopathy, abbreviated as myositis, is a heterogeneous disease characterized by proximal muscle involvement and chronic inflammation, primarily affecting the lungs. The aim of this study was to establish a stable idiopathic inflammatory myopathy (IIM)-associated interstitial lung disease (ILD) mouse model and evaluate the effects of zanubrutinib on IIM-ILD. We induced an IIM lung involvement model in balb/c mice through subcutaneous injection of skeletal muscle homogenate and intraperitoneal injection of pertussis toxin. We observed that the combination of skeletal muscle protein and pertussis toxin in balb/c mice could establish a stable IIM lung involvement model, characterized by muscle inflammation and pulmonary interstitial changes similar to clinical pathology. Zanubrutinib alleviated IIM and ILD, and its anti-inflammatory properties were demonstrated by a reduction in inflammatory cells and inflammatory factors in bronchoalveolar lavage fluid and bronchial inflammation. Its anti-inflammatory and anti-fibrotic effects were mainly achieved through the inhibition of BTK and NF-κB phosphorylation. This study established a stable IIM-ILD animal model and demonstrated for the first time that the BTK inhibitor zanubrutinib effectively attenuates experimental IIM-ILD in this model.

Integration of microbiomics, metabolomics, and transcriptomics reveals the therapeutic mechanism underlying Fuzheng-Qushi decoction for the treatment of lipopolysaccharide-induced lung injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzheng-Qushi decoction (FZQS) is a practical Chinese herbal formula for relieving cough and fever. Therefore, the action and specific molecular mechanism of FZQS in the treatment of lung injury with cough and fever as the main symptoms need to be further investigated.

AIMS OF THE STUDY

To elucidate the protective effects of FZQS against lung injury in mice and reveal its potential targets and key biological pathways for the treatment of lung injury based on transcriptomics, microbiomics, and untargeted metabolomics analyses.

MATERIALS AND METHODS

Lipopolysaccharide (LPS) was used to induce a mouse model of lung injury, followed by the administration of FZQS. ELISA was used to detect IL-1β, IL-6, IL-17A, IL-4, IL-10, and TNF-α, in mouse lung tissues. Macrophage polarization and neutrophil activation were measured by flow cytometry. RNA sequencing (RNA-seq) was applied to screen for differentially expressed genes (DEGs) in lung tissues. RT-qPCR and Western blot assays were utilized to validate key DEGs and target proteins in lung tissues. 16S rRNA sequencing was employed to characterize the gut microbiota of mice. Metabolites in the gut were analyzed using untargeted metabolomics.

RESULTS

FZQS treatment significantly ameliorated lung histopathological damage, decreased pro-inflammatory cytokine levels, and increased anti-inflammatory cytokine levels. M1 macrophage levels in the peripheral blood decreased, M2 macrophage levels increased, and activated neutrophils were inhibited in mice with LPS-induced lung injury. Importantly, transcriptomic analysis showed that FZQS downregulated macrophage and neutrophil activation and migration and adhesion pathways by reversing 51 DEGs, which was further confirmed by RT-qPCR and Western blot analysis. In addition, FZQS modulated the dysbiosis of the gut microbiota by reversing the abundance of Corynebacterium, Facklamia, Staphylococcus, Paenalcaligenes, Lachnoclostridium, norank_f_Muribaculaceae, and unclassified_f_Lachnospiraceae. Meanwhile, metabolomics analysis revealed that FZQS significantly regulated tryptophan metabolism by reducing the levels of 3-Indoleacetonitrile and 5-Hydroxykynurenine.

CONCLUSION

FZQS effectively ameliorated LPS-induced lung injury by inhibiting the activation, migration, and adhesion of macrophages and neutrophils and modulating gut microbiota and its metabolites.

PBMC-mediated modulation of macrophage polarization in RAW264.7 cells through STAT1/STAT6 signaling cascades

Peripheral blood mononuclear cells (PBMC), sourced autologously, offer numerous advantages when procured: easier acquisition process, no in vitro amplification needed, decreased intervention and overall increased acceptability make PBMC an attractive candidate for cell therapy treatment. However, the exact mechanism by which PBMC treat diseases remains poorly understood. Immune imbalance is the pathological basis of many diseases, with macrophages playing a crucial role in this process. However, research on the role and mechanisms of PBMC in regulating macrophages remains scarce. This study employed an in vitro co-culture model of PBMC and RAW264.7 macrophages to explore the role and mechanisms of PBMC in regulating macrophages. The results showed that the co-culturing led to decreased expression of inflammatory cytokines and increased expression of anti-inflammatory cytokines in RAW264.7 or in the culture supernatant. Additionally, the pro-inflammatory, tissue matrix-degrading M1 macrophages decreased, while the anti-inflammatory, matrix-synthesizing, regenerative M2 macrophages increased in both RAW264.7 and monocytes within PBMC. Moreover, co-cultured macrophages exhibited a significantly decreased p-STAT1/STAT1 ratio, while the p-STAT6/STAT6 ratio significantly increased. This suggests that PBMC may inhibit M1 macrophage polarization by blocking STAT1 signaling cascades and may promote M2 macrophage polarization through the activation of STAT6 signaling cascades. Overall, this study sheds light on the role and mechanism of PBMC in regulating macrophages. Moreover, it was found that monocytes within co-cultured PBMC differentiated into M2 macrophages in the presence of macrophages. This finding provides experimental evidence for the use of PBMC in treating inflammatory diseases, especially macrophage-depleting inflammatory diseases such as osteoarthritis.

Deciphering the therapeutic potential of Myeloid-Specific JAK2 inhibition in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by severe inflammation and pulmonary dysfunction. Despite advancements in critical care, effective pharmacological interventions for ARDS remain elusive. While Janus kinase 2 (JAK2) inhibitors have emerged as an innovative treatment for numerous autoinflammatory diseases, their therapeutic potential in ARDS remains unexplored. In this study, we investigated the contribution of JAK2 and its underlying mechanisms in ARDS utilizing myeloid-specific JAK2 knockout murine models alongside a pharmacological JAK2 inhibitor. Notably, myeloid-specific JAK2 knockout led to a notable attenuation of ARDS induced by intratracheal administration of LPS, accompanied by reduced levels of neutrophils and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung tissue. Intriguingly, the ameliorative effects were abolished upon the depletion of monocyte-derived alveolar macrophages (Mo-AMs) rather than tissue-resident alveolar macrophages (TR-AMs). JAK2 deficiency markedly reversed LPS-induced activation of STAT5 in macrophages. Remarkably, pharmacological JAK2 inhibition using baricitinib failed to substantially alleviate neutrophils infiltration, implying that specific inhibition of JAK2 in Mo-AMs is imperative for ARDS amelioration. Collectively, our data suggest that JAK2 may mitigate ARDS progression through the JAK2 pathway in Mo-AMs, underscoring JAK2 in alveolar macrophages, particularly Mo-AMs, as a promising therapeutic target for ARDS treatment.

Impact of leukemia-associated macrophages on the progression and therapy response of chronic lymphocytic leukemia

The treatment landscape of chronic lymphocytic leukemia (CLL) has advanced remarkably over the past decade. The advent and approval of the BTK inhibitor ibrutinib and BCL-2 inhibitor venetoclax, as well as monoclonal anti-CD20 antibodies rituximab and obinutuzumab, have resulted in deep remissions and substantially improved survival outcomes for patients. However, CLL remains a complex disease with many patients still experiencing relapse and unsatisfactory treatment responses. CLL cells are highly dependent on their pro-leukemic tumor microenvironment (TME), which comprises different cellular and soluble factors. A large body of evidence suggests that CLL-associated macrophages shaped by leukemic cells play a pivotal role in maintaining CLL cell survival. In this review, we summarize the pro-survival interactions between CLL cells and macrophages, as well as the impact of the current first-line treatment agents, including ibrutinib, venetoclax, and CD20 antibodies on leukemia-associated macrophages.

Icariin attenuates asthmatic airway inflammation via modulating alveolar macrophage activation based on network pharmacology and in vivo experiments

BACKGROUND

Icariin (ICA) inhibits inflammatory response in various diseases, but the mechanism underlying ICA treating airway inflammation in asthma needs further understood. We aimed to predict and validate the potential targets of ICA against asthma-associated airway inflammation using network pharmacology and experiments.

METHODS

The ovalbumin-induced asthma-associated airway inflammation mice model was established. The effects of ICA were evaluated by behavioral, airway hyperresponsiveness, lung pathological changes, inflammatory cell and cytokines counts. Next, the corresponding targets of ICA were mined via the SEA, CTD, HERB, PharmMapper, Symmap database and the literature. Pubmed-Gene and GeneCards databases were used to screen asthma and airway inflammation-related targets. The overlapping targets were used to build an interaction network, analyze gene ontology and enrich pathways. Subsequently, flow cytometry, quantitative real-time PCR and western blotting were employed for validation.

RESULTS

ICA alleviated the airway inflammation of asthma; 402 targets of ICA, 5136 targets of asthma and 4531 targets of airway inflammation were screened; 216 overlapping targets were matched and predicted ICA possesses the potential to modulate asthmatic airway inflammation by macrophage activation/polarization. Additionally, ICA decreased M1 but elevated M2. Potential targets that were disrupted by asthma inflammation were restored by ICA treatment.

CONCLUSIONS

ICA alleviates airway inflammation in asthma by inhibiting the M1 polarization of alveolar macrophages, which is related to metabolic reprogramming. Jun, Jak2, Syk, Tnf, Aldh2, Aldh9a1, Nos1, Nos2 and Nos3 represent potential targets of therapeutic intervention. The present study enhances understanding of the anti-airway inflammation effects of ICA, especially in asthma.

The STAT3 inhibitor B9 alleviates lipopolysaccharide-induced acute lung injury through its anti-inflammatory effects

The development of acute lung injury (ALI), a common respiratory condition with multiple causes, is significantly influenced by the pro-inflammatory environment of signal transducer and activator of transcription 3 (STAT3) in macrophages. Our study aimed to evaluate the anti-inflammatory effects of B9 (N-(4-hydroxyphenyl)-9, 10-dioxo-9, 10-dihydroanthracene-2-sulfonamide), a novel inhibitor targeting the STAT3 SH2 domain, in macrophages and to assess its therapeutic potential for ALI using a mouse model of lipopolysaccharide (LPS)-induced ALI. We found that B9 (30 mg/kg) significantly reduced lung pathological damage and neutrophil infiltration caused by the intratracheal administration of LPS. Additionally, the high expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in alveolar lavage fluid was also inhibited by B9 treatment. The decreased expression of CD86 and increased CD206 in lung tissue demonstrated the anti-inflammatory effect of B9, which was due to its inhibition of the STAT3 signaling pathway in macrophages of ALI mice. Furthermore, B9 suppressed the activation of RAW264.7 cells induced by LPS, characterized by its ability to inhibit the activation of iNOS and STAT3 in a dose-dependent manner, as well as reduce the secretion of IL-6 and IL-1β. The in vivo preliminary safety evaluation indicated that B9 had a favorable safety profile at the administered doses. These results suggest that B9 exerts a therapeutic effect on LPS-induced ALI, potentially by preventing the phosphorylation of STAT3 Y705 and S727 without affecting the STAT3 protein level. Taken together, these findings provide a foundation for developing B9 as a novel anti-inflammatory agent for ameliorating LPS-induced ALI.

ARC@DPBNPs suppress LPS-induced acute lung injury via inhibiting macrophage pyroptosis and M1 polarization by ERK pathway in mice

AIM OF THE STUDY

Exploring the protective effect of ARC@DPBNP on lipopolysaccharides (LPS)-induced ALI and its underlying mechanism.

MATERIALS AND METHODS

ALI model was established by intransally administrating LPS (4 mg/kg) into C57BL/6 mice. The suppression effects of ALI was first compared between ARC (intragastric administrated, with doses ranging from 10 to 80 mg/kg) and ARC@BPBNPs (intratracheally administrated, with doses ranging from 1 to 4 mg/kg). Changes in lung histology post intratracheal intervention of 3 mg/kg ARC@DPBNPs were detected. The expression of pyrotosis pathway-related proteins in lungs as well as in RAW264.7 cells was detected by western blotting. The ASC expression in lung macrophages was examined using immune-fluorescent staining. The polarization of RAW264.7 cells and lung macrophages were detected by flow cytometry. The network pharmacology was constructed by Cytoscape, and the molecular docking was perfomed by AutoDock Vina.

RESULTS

Docking predicted the high affinity of ARC to MAPK1 (ERK2). HE staining showed that ARC@DPBNPs attenuated LPS-induced ALI at a remarkably lower dose than ARC. The improved histopathological changes, lung W/D weight ratio, and decreased of inflammatory factor levels in lung collectively demonstrated the alleviation effects of ARC@DPBNPs. Compared with the LPS group, ARC@DPBNPs down-regulated the ERK pathway, resulted in a suppression of the macrophage pyroptosis and M1 polarization. This suppression effects could be removed by the ERK activator Ro 67-7476.

CONCLUSION

ARC@DPBNPs attenuated ALI by suppressing LPS-induced macrophage pyroptosis and polarization, probably through down-regulation of the ERK pathway.

Modulation of experimental acute lung injury by exosomal miR-7704 from mesenchymal stromal cells acts through M2 macrophage polarization

Acute lung injury (ALI) is a life-threatening condition with limited treatment options. The pathogenesis of ALI involves macrophage-mediated disruption and subsequent repair of the alveolar barriers, which ultimately results in lung damage and regeneration, highlighting the pivotal role of macrophage polarization in ALI. Although exosomes derived from mesenchymal stromal cells have been established as influential modulators of macrophage polarization, the specific role of exosomal microRNAs (miRNAs) remains underexplored. This study aimed to elucidate the role of specific exosomal miRNAs in driving macrophage polarization, thereby providing a reference for developing novel therapeutic interventions for ALI. We found that miR-7704 is the most abundant and efficacious miRNA for promoting the switch to the M2 phenotype in macrophages. Mechanistically, we determined that miR-7704 stimulates M2 polarization by inhibiting the MyD88/STAT1 signaling pathway. Notably, intra-tracheal delivery of miR-7704 alone in a lipopolysaccharide-induced murine ALI model significantly drove M2 polarization in lung macrophages and remarkably restored pulmonary function, thus increasing survival. Our findings highlight miR-7704 as a valuable tool for treating ALI by driving the beneficial M2 polarization of macrophages. Our findings pave the way for deeper exploration into the therapeutic potential of exosomal miRNAs in inflammatory lung diseases.

S100A9-/- alleviates LPS-induced acute lung injury by regulating M1 macrophage polarization and inhibiting pyroptosis via the TLR4/MyD88/NFκB signaling axis

Acute lung injury (ALI) is characterized by pulmonary diffusion abnormalities that may progress to multiple-organ failure in severe cases. There are limited effective treatments for ALI, which makes the search for new therapeutic avenues critically important. Macrophages play a pivotal role in the pathogenesis of ALI. The degree of macrophage polarization is closely related to the severity and prognosis of ALI, and S100A9 promotes M1 polarization of macrophages. The present study assessed the effects of S100A9-gene deficiency on macrophage polarization and acute lung injury. Our cohort study showed that plasma S100A8/A9 levels had significant diagnostic value for pediatric pneumonia and primarily correlated with monocyte-macrophages and neutrophils. We established a lipopolysaccharide (LPS)-induced mouse model of acute lung injury and demonstrated that knockout of the S100A9 gene mitigated inflammation by suppressing the secretion of pro-inflammatory cytokines, reducing the number of inflammatory cells in the bronchoalveolar lavage fluid, and inhibiting cell apoptosis, which ameliorated acute lung injury in mice. The in vitro and in vivo mechanistic studies demonstrated that S100A9-gene deficiency inhibited macrophage M1 polarization and reduced the levels of pulmonary macrophage chemotactic factors and inflammatory cytokines by suppressing the TLR4/MyD88/NF-κB signaling pathway and reversing the expression of the NLRP3 pyroptosis pathway, which reduced cell death. In conclusion, S100A9-gene deficiency alleviated LPS-induced acute lung injury by inhibiting macrophage M1 polarization and pyroptosis via the TLR4/MyD88/NFκB pathway, which suggests a potential therapeutic strategy for the treatment of ALI.

Targeting Keap1 with Inulae Herba activated the Nrf2 receptor to alleviate LPS-mediated acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Inulae Herba (IH) is known as Jinfeicao recorded in Chinese Pharmacopoeia with effects of lowering qi and eliminating phlegm, and used for the treatment of pulmonary diseases. However, its protective mechanism on pulmonary diseases, especially acute lung injury (ALI), is still undefined.

AIM OF THE STUDY

This study aimed to explore anti-inflammatory and anti-oxidation effects of IH and its underlying mechanism for treating ALI.

MATERIALS AND METHODS

We constructed a lipopolysaccharide (LPS)-ALI mouse model to reveal the therapeutical effect of IH. Western blot, real-time quantitative PCR, flow cytometry, small RNA interference, immunohistochemical staining, and the dual-luciferase experiment were performed to study the mechanism of IH for treating ALI.

RESULTS

IH attenuated LPS-mediated pathological changes (e.g. pneumonedema and pulmonary congestion) through inactivation of macrophages in an ALI mouse model. The result of flow cytometry demonstrated that IH regulated the homeostasis of M1 (CD80+CD206-) and M2 (CD80+CD206+) phenotype macrophages. Furthermore, IH suppressed mRNA expressions of M1 phenotype markers, such as iNOS and IL-6, whereas promoted mRNA expressions of M2 phenotype markers, such as ARG1 and RETNLA in LPS-mediated mice. Notably, IH targeted Keap1 to activate the Nrf2 receptor, exerting its anti-inflammatory and anti-oxidation effects proved by using immunohistochemical staining, dual-luciferase, and Keap1 knockdown technologies.

CONCLUSION

These findings suggested that targeting Keap1 with IH alleviated LPS-mediated ALI, and it could serve as a herbal agent for developing anti-ALI drugs.

Expression of Angiopoietin-2 in Lung Tissue of Juvenile SD Rats with Lipopolysaccharide-Induced Acute Lung Injury and the Role of Ulinastatin

This study aimed to observe the expression of angiopoietin-2 (Ang-2) in the lung tissue of juvenile SD rats with lipopolysaccharide (LPS)-induced acute lung injury (ALI) and to clarify the role of ulinastatin (UTI). Ninety 18-21-day-old juvenile SD male rats were randomly divided into five groups (n = 18). ALI rat model was established by intraperitoneal injection of LPS (LPS 10 mg/kg), while the control group was given the same dose of normal saline. The UTI intervention group was given the injection of UTI (5000 U/mL) immediately after the injection of LPS, which was divided into UTI low-dose group (LPS + 5 ml/kg UTI), UTI medium-dose group (LPS + 10 ml/kg UTI), and UTI high-dose group (LPS + 20 ml/kg UTI).The respiratory status of each group of rats was observed, and six rats were randomly selected to be killed in each group at 6, 12, and 24 h, and the lung tissues were dissected and retained. The pathological changes of the lung tissues were observed by hematoxylin-eosin (HE) staining, the expression levels and locations of Ang-2 and vascular endothelial growth factor (VEGF) in lung tissue were observed by immunohistochemical staining, and the expressions of genes and proteins of Ang-2 and VEGF were detected by quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. Three hours after intraperitoneal injection, rats in the model group developed shortness of breath and the developed respiratory distress progressed over time. The lung pathological changes in the model group were obvious compared with those in the control group, and gradually worsened with time, and the pathological changes of lung in the rats in the UTI intervention group were reduced compared with those in the model group. At different time points, the expressions of Ang-2 and VEGF in the lung tissue of rats in the model group were higher than those in the control group, and were lower in the UTI intervention group than those in the model group. The expressions of Ang-2 and VEGF protein were lower in the low-dose group of UTI group than those in the high-dose group of UTI group at different time points (P < 0.05), and the expressions of Ang-2 and VEGF protein in the low-dose group of UTI were significantly lower than those in the medium-dose group at 12 h and 24 h (P < 0.05). The expression of Ang-2 was increased in the lung tissue of juvenile SD rats with LPS-induced ALI, and was associated with the degree of lung injury. UTI might attenuate LPS-induced ALI by inhibiting the expression of Ang-2 in lung tissue, and the low dose was more obvious than the medium and high dose.

Qinhuo Shanggan oral solution resolves acute lung injury by down-regulating TLR4/NF-κB signaling cascade and inhibiting NLRP3 inflammasome activation

Acute lung injury (ALI) is a common condition, particularly in the COVID-19 pandemic, which is distinguished by sudden onset of respiratory insufficiency with tachypnea, oxygen-refractory cyanosis, reduced lung compliance and diffuse infiltration of pulmonary alveoli. It is well-established that increasing activity of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling axis and the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation are associated with the pathogenesis of ALI. Since ALI poses a huge challenge to human health, it is urgent to tackle this affliction with therapeutic intervention. Qinhuo Shanggan oral solution (QHSG), a traditional Chinese herbal formula, is clinically used for effective medication of various lung diseases including ALI, with the action mechanism obscure. In the present study, with the rat model of lipopolysaccharide (LPS)-induced ALI, QHSG was unveiled to ameliorate ALI by alleviating the pathological features, reversing the alteration in white blood cell profile and impeding the production of inflammatory cytokines through down-regulation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. In LPS-stimulated RAW264.7 mouse macrophages, QHSG was discovered to hinder the generation of inflammatory cytokines by lessening TLR4/NF-κB signaling pathway activity and weakening NLRP3 inflammasome activation. Taken together, QHSG may resolve acute lung injury, attributed to its anti-inflammation and immunoregulation by attenuation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. Our findings provide a novel insight into the action mechanism of QHSG and lay a mechanistic foundation for therapeutic intervention in acute lung injury with QHSG in clinical practice.

Alveolar macrophages in tissue homeostasis, inflammation, and infection: evolving concepts of therapeutic targeting

Alveolar macrophages (AMs) are the sentinel cells of the alveolar space, maintaining homeostasis, fending off pathogens, and controlling lung inflammation. During acute lung injury, AMs orchestrate the initiation and resolution of inflammation in order to ultimately restore homeostasis. This central role in acute lung inflammation makes AMs attractive targets for therapeutic interventions. Single-cell RNA-Seq and spatial omics approaches, together with methodological advances such as the generation of human macrophages from pluripotent stem cells, have increased understanding of the ontogeny, function, and plasticity of AMs during infectious and sterile lung inflammation, which could move the field closer to clinical application. However, proresolution phenotypes might conflict with proinflammatory and antibacterial responses. Therefore, therapeutic targeting of AMs at vulnerable time points over the course of infectious lung injury might harbor the risk of serious side effects, such as loss of antibacterial host defense capacity. Thus, the identification of key signaling hubs that determine functional fate decisions in AMs is of the utmost importance to harness their therapeutic potential.

Eriocalyxin B ameliorated Crohn's disease-like colitis by restricting M1 macrophage polarization through JAK2/STAT1 signalling

BACKGROUND AND AIMS

M1 polarization of macrophages in the intestine is an important maintenance factor of the inflammatory response in Crohn's disease (CD). Eriocalyxin B (EriB) is a natural medicine that antagonizes inflammation. Our study aimed to determine the effects of EriB on CD-like colitis in mice, as well as the possible mechanism.

METHODS

2,4,6-trinitrobenzene sulfonic acid (TNBS) mice and Il-10^-/- mice were used as CD animal models, and the therapeutic effect of EriB on CD-like colitis in mice was addressed by the disease activity index (DAI) score, weight change, histological analysis and flow cytometry assay. To assess the direct role of EriB in regulating macrophage polarization, bone marrow-derived macrophages (BMDMs) were induced to M1 or M2 polarization separately. Molecular docking simulations and blocking experiments were performed to explore the potential mechanisms by which EriB regulates the macrophage polarization.

RESULTS

EriB treatment reduced body weight loss, DAI score and histological score, demonstrating the improvement of colitis symptoms in mice. In vivo and in vitro experiments both showed that EriB decreased the M1 polarization of macrophages, and suppressed the release of proinflammatory cytokines (IL-1β, TNF-α and IL-6) in mouse colons and BMDMs. The activation of Janus kinase 2/signal transducer and activator of transcription 1 (JAK2/STAT1) signals could be inhibited by EriB, which may be related to the regulation of EriB on M1 polarization.

CONCLUSIONS

EriB inhibits the M1 polarization of macrophages by attenuating the JAK2/STAT1 pathway, which partially explains the potential mechanism by which EriB ameliorates colitis in mice, and provides a new regimen for the clinical treatment of CD.

Macrophage Polarization: An Important Candidate Regulator for Lung Diseases

Macrophages are crucial components of the immune system and play a critical role in the initial defense against pathogens. They are highly heterogeneous and plastic and can be polarized into classically activated macrophages (M1) or selectively activated macrophages (M2) in response to local microenvironments. Macrophage polarization involves the regulation of multiple signaling pathways and transcription factors. Here, we focused on the origin of macrophages, the phenotype and polarization of macrophages, as well as the signaling pathways associated with macrophage polarization. We also highlighted the role of macrophage polarization in lung diseases. We intend to enhance the understanding of the functions and immunomodulatory features of macrophages. Based on our review, we believe that targeting macrophage phenotypes is a viable and promising strategy for treating lung diseases.

Plasticity towards Rigidity: A Macrophage Conundrum in Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, and ultimately fatal diffuse parenchymal lung disease. The molecular mechanisms of fibrosis in IPF patients are not fully understood and there is a lack of effective treatments. For decades, different types of drugs such as immunosuppressants and antioxidants have been tested, usually with unsuccessful results. Although two antifibrotic drugs (Nintedanib and Pirfenidone) are approved and used for the treatment of IPF, side effects are common, and they only slow down disease progression without improving patients' survival. Macrophages are central to lung homeostasis, wound healing, and injury. Depending on the stimulus in the microenvironment, macrophages may contribute to fibrosis, but also, they may play a role in the amelioration of fibrosis. In this review, we explore the role of macrophages in IPF in relation to the fibrotic processes, epithelial-mesenchymal transition (EMT), and their crosstalk with resident and recruited cells and we emphasized the importance of macrophages in finding new treatments.