Pulmonary CCR2+CD4+ T cells are immune regulatory and attenuate lung fibrosis development

Bortezomib restrains M2 polarization and reduces CXCL16-associated CXCR6+CD4 T cell chemotaxis in bleomycin-induced pulmonary fibrosis

BACKGROUND

The development of pulmonary fibrosis involves a cascade of events, in which inflammation mediated by immune cells plays a pivotal role. Chemotherapeutic drugs have been shown to have dual effects on fibrosis, with bleomycin exacerbating pulmonary fibrosis and bortezomib alleviating tissue fibrotic processes. Understanding the intricate interplay between chemotherapeutic drugs, immune responses, and pulmonary fibrosis is likely to serve as the foundation for crafting tailored therapeutic strategies.

METHODS

A model of bleomycin-induced pulmonary fibrosis was established, followed by treatment with bortezomib. Tissue samples were collected for analysis of immune cell subsets and functional assessment by flow cytometry and in vitro cell experiments. Additionally, multi-omics analysis was conducted to further elucidate the expression of chemokines and chemokine receptors, as well as the characteristics of cell populations.

RESULTS

Here, we observed that the expression of CXCL16 and CXCR6 was elevated in the lung tissue of a pulmonary fibrosis model. In the context of pulmonary fibrosis or TGF-β1 stimulation in vitro, macrophages exhibited an M2-polarized phenotype and secreted more CXCL16 than those of the control group. Moreover, flow cytometry revealed increased expression levels of CD69 and CXCR6 in pulmonary CD4 T cells during fibrosis progression. The administration of bortezomib alleviated bleomycin-induced pulmonary fibrosis, accompanied by reduced ratio of M2-polarized macrophages and decreased accumulation of CD4 T cells expressing CXCR6.

CONCLUSIONS

Our findings provide insights into the key immune players involved in bleomycin-induced pulmonary fibrosis and offer preclinical evidence supporting the repurposing strategy and combination approaches to reduce lung fibrosis.

Targeting transitioning lung monocytes/macrophages as treatment strategies in lung disease related to environmental exposures

BACKGROUND

Environmental/occupational exposures cause significant lung diseases. Agricultural organic dust extracts (ODE) and bacterial component lipopolysaccharide (LPS) induce recruited, transitioning murine lung monocytes/macrophages, yet their cellular role remains unclear.

METHODS

CCR2 RFP+ mice were intratracheally instilled with high concentration ODE (25%), LPS (10 μg), or gram-positive peptidoglycan (PGN, 100 μg) for monocyte/macrophage cell-trafficking studies. CCR2 knockout (KO) mice and administration of intravenous clodronate liposomes strategies were employed to reduce circulating monocytes available for lung recruitment following LPS exposure. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected. Pro-inflammatory and/or pro-fibrotic cytokines, chemokines, and lung extracellular matrix mediators were quantitated by ELISA. Infiltrating lung cells including monocyte/macrophage subpopulations, neutrophils, and lymphocytes were characterized by flow cytometry. Lung histopathology, collagen content, vimentin, and post-translational protein citrullination and malondialdehyde acetaldehyde (MAA) modification were quantitated. Parametric statistical tests (one-way ANOVA, Tukey'smultiple comparison) and nonparametric statistical (Kruskal-Wallis, Dunn's multiple comparison) tests were used following Shapiro-Wilk testing for normality.

RESULTS

Intratracheal instillation of ODE, LPS, or PGN robustly induced the recruitment of inflammatory CCR2+ CD11cintCD11bhi monocytes/macrophages and both CCR2+ and CCR2- CD11c-CD11bhi monocytes at 48 h. There were also increases in CCR2+ CD4+ and CD8+ T cells and NK cells. Despite reductions in LPS-induced lung infiltrating CD11cintCD11bhi cells (54% reduction), CCR2 knockout (KO) mice were not protected against LPS-induced inflammatory and pro-fibrotic consequences. Instead, compensatory increases in lung neutrophils and CCL2 and CCL7 release occurred. In contrast, the depletion of circulating monocytes through the administration of intravenous clodronate (vs. vehicle) liposomes 24 h prior to LPS exposure reduced LPS-induced infiltrating CD11cintCD11bhi monocyte-macrophage subpopulation by 59% without compensatory changes in other cell populations. Clodronate liposome pre-treatment significantly reduced LPS-induced IL-6 (66% reduction), matrix metalloproteinases (MMP)-3 (36%), MMP-8 (57%), tissue inhibitor of metalloproteinases (61%), fibronectin (38%), collagen content (22%), and vimentin (40%). LPS-induced lung protein citrullination and MAA modification, post-translational modifications implicated in lung disease, were reduced (39% and 48%) with clodronate vs. vehicle liposome.

CONCLUSION

Highly concentrated environmental/occupational exposures induced the recruitment of CCR2+ and CCR2- transitioning monocyte-macrophage and monocyte subpopulations and targeting peripheral monocytes may reduce the adverse lung consequences resulting from exposures to LPS-enriched inhalants.

Dynamics of host immune responses and a potential function of Trem2hi interstitial macrophages in Pneumocystis pneumonia

BACKGROUND

Pneumocystis pneumonia (PCP) is a life-threatening opportunistic fungal infection with a high mortality rate in immunocompromised patients, ranging from 20 to 80%. However, current understanding of the variation in host immune response against Pneumocystis across different timepoints is limited.

METHODS

In this study, we conducted a time-resolved single-cell RNA sequencing analysis of CD45+ cells sorted from lung tissues of mice infected with Pneumocystis. The dynamically changes of the number, transcriptome and interaction of multiply immune cell subsets in the process of Pneumocystis pneumonia were identified according to bioinformatic analysis. Then, the accumulation of Trem2hi interstitial macrophages after Pneumocystis infection was verified by flow cytometry and immunofluorescence. We also investigate the role of Trem2 in resolving the Pneumocystis infection by depletion of Trem2 in mouse models.

RESULTS

Our results characterized the CD45+ cell composition of lung in mice infected with Pneumocystis from 0 to 5 weeks, which revealed a dramatic reconstitution of myeloid compartments and an emergence of PCP-associated macrophage (PAM) following Pneumocystis infection. PAM was marked by the high expression of Trem2. We also predicted that PAMs were differentiated from Ly6C+ monocytes and interacted with effector CD4+ T cell subsets via multiple ligand and receptor pairs. Furthermore, we determine the surface markers of PAMs and validated the presence and expansion of Trem2hi interstitial macrophages in PCP by flow cytometry. PAMs secreted abundant pro-inflammation cytokines, including IL-6, TNF-α, GM-CSF, and IP-10. Moreover, PAMs inhibited the proliferation of T cells, and depletion of Trem2 in mouse lead to reduced fungal burden and decreased lung injury in PCP.

CONCLUSION

Our study delineated the dynamic transcriptional changes in immune cells and suggests a role for PAMs in PCP, providing a framework for further investigation into PCP's cellular and molecular basis, which could provide a resource for further discovery of novel therapeutic targets.

Computational prognostic evaluation of Alzheimer's drugs from FDA-approved database through structural conformational dynamics and drug repositioning approaches

Drug designing is high-priced and time taking process with low success rate. To overcome this obligation, computational drug repositioning technique is being promptly used to predict the possible therapeutic effects of FDA approved drugs against multiple diseases. In this computational study, protein modeling, shape-based screening, molecular docking, pharmacogenomics, and molecular dynamic simulation approaches have been utilized to retrieve the FDA approved drugs against AD. The predicted MADD protein structure was designed by homology modeling and characterized through different computational resources. Donepezil and galantamine were implanted as standard drugs and drugs were screened out based on structural similarities. Furthermore, these drugs were evaluated and based on binding energy (Kcal/mol) profiles against MADD through PyRx tool. Moreover, pharmacogenomics analysis showed good possible associations with AD mediated genes and confirmed through detail literature survey. The best 6 drug (darifenacin, astemizole, tubocurarine, elacridar, sertindole and tariquidar) further docked and analyzed their interaction behavior through hydrogen binding. Finally, MD simulation study were carried out on these drugs and evaluated their stability behavior by generating root mean square deviation and fluctuations (RMSD/F), radius of gyration (Rg) and soluble accessible surface area (SASA) graphs. Taken together, darifenacin, astemizole, tubocurarine, elacridar, sertindole and tariquidar displayed good lead like profile as compared with standard and can be used as possible therapeutic agent in the treatment of AD after in-vitro and in-vivo assessment.

Zfp362 potentiates murine colonic inflammation by constraining Treg cell function rather than promoting Th17 cell differentiation

Mucosal barrier integrity and pathogen clearance is a complex process influenced by both Th17 and Treg cells. Previously, we had described the DNA methylation profile of Th17 cells and identified Zinc finger protein (Zfp)362 to be uniquely demethylated. Here, we generated Zfp362-/- mice to unravel the role of Zfp362 for Th17 cell biology. Zfp362-/- mice appeared clinically normal, showed no phenotypic alterations in the T-cell compartment, and upon colonization with segmented filamentous bacteria, no effect of Zfp362 deficiency on Th17 cell differentiation was observed. By contrast, Zfp362 deletion resulted in increased frequencies of colonic Foxp3+ Treg cells and IL-10+ and RORγt+ Treg cell subsets in mesenteric lymph nodes. Adoptive transfer of naïve CD4+ T cells from Zfp362-/- mice into Rag2-/- mice resulted in a significantly lower weight loss when compared with controls receiving cells from Zfp362+/+ littermates. However, this attenuated weight loss did not correlate with alterations of Th17 cells but instead was associated with an increase of effector Treg cells in mesenteric lymph nodes. Together, these results suggest that Zfp362 plays an important role in promoting colonic inflammation; however, this function is derived from constraining the effector function of Treg cells rather than directly promoting Th17 cell differentiation.

The chemokine CCL1 facilitates pulmonary fibrosis by promoting macrophage migration and M2 polarization

Macrophage M2 polarization has been identified in the pathogenesis of pulmonary fibrosis (PF), but the mediators that drive the macrophage M2 program in PF need to be clarified. We showed that the expression of AMFR and CCR8, two known receptors of CCL1, was increased in macrophages from lungs of mice with bleomycin (BLM)-induced PF. Deficiency in either AMFR or CCR8 in macrophages protected mice from BLM-induced PF. In vitro experiments revealed that CCL1 recruited macrophages by binding to its classical receptor CCR8 and drove the macrophage M2 phenotype via its interaction with the recently identified receptor AMFR. Mechanistic studies revealed that the CCL1-AMFR interaction enhanced CREB/C/EBPβ signaling to promote the macrophage M2 program. Together, our findings reveal that CCL1 acts as a mediator of macrophage M2 polarization and could be a therapeutic target in PF.

Single-cell sequencing analysis fibrosis provides insights into the pathobiological cell types and cytokines of radiation-induced pulmonary fibrosis

BACKGROUND

Radiotherapy is an essential treatment for chest cancer. Radiation-induced pulmonary fibrosis (RIPF) is an almost irreversible interstitial lung disease; however, its pathogenesis remains unclear.

METHODS

We analyzed specific changes in cell populations and potential markers by using single-cell sequencing datasets from the Sequence Read Archive database, PERFORMED from control (0 Gy) and thoracic irradiated (20 Gy) mouse lungs at day 150 post-radiation. We performed IHC and ELISA on lung tissue and cells to validate the potential marker cytokines identified by the analysis on rat thoracic irradiated molds (30 Gy).

RESULTS

Single-cell sequencing analysis showed changes in abundance across cell types and at the single-cell level, with B and T cells showing the most significant changes in abundance. And four cytokines, CCL5, ICAM1, PF4, and TNF, were significantly upregulated in lung tissues of RIPF rats and cell supernatants after ionizing radiation.

CONCLUSION

Cytokines CCL5, ICAM1, PF4, and TNF may play essential roles in radiation pulmonary fibrosis. They are potential targets for the treatment of radiation pulmonary fibrosis.

A novel quantification method of lung fibrosis based on Micro-CT images developed with the optimized pulmonary fibrosis mice model induced by bleomycin

Background and aims

Idiopathic pulmonary fibrosis (IPF) is a fibrosing lung disease with unknown etiology, leading to cough and dyspnoea, which is also one of the most common sequelae affecting the quality of life of COVID-19 survivors. There is no cure for IPF patients. We aim to develop a reliable IPF animal model with quantification of fibrosis based on Micro-Computer Tomography (micro-CT) images for the new drug discovery, because different bleomycin administration routes, doses, and intervals are reported in the literature, and there is no quantitative assessment of pulmonary fibrosis based on micro-CT images in animal studies.

Methods

We compared three dosages (1.25 mg/kg, 2.5 mg/kg, and 5 mg/kg) of intratracheal bleomycin administration and experiment intervals (14 and 21 days) in C57BL/6 mice by investigating survival rates, pulmonary histopathology, micro-CT, peripheral CD4⁺ & CD8⁺ cells, and cytokines. Moreover, a simple and reliable new method was developed for scoring fibrosis in live mice based on Micro-CT images by using Image J software, which transfers the dark sections in pulmonary Micro-CT images to light colors on a black background.

Results

The levels of hydroxyproline, inflammation cytokine, fibrotic pathological changes, and collagen deposition in the lungs of mice were bleomycin dose-dependent and time-dependent as well as the body weight loss. Based on the above results, the mice model at 21 days after being given bleomycin at 1.25 mg/kg has optimal pulmonary fibrosis with a high survival rate and low toxicity. There is a significant decrease in the light area (gray value at 9.86 ± 0.72) in the BLM mice, indicating that a significant decrease in the alveolar air area was observed in BLM injured mice compared to normal groups (###p < 0.001), while the Pirfenidone administration increased the light area (gray value) to 21.71 ± 2.95 which is close to the value observed in the normal mice (gray value at 23.23 ± 1.66), which is consistent with the protein levels of Col1A1, and α-SMA. Notably, the standard deviations for the consecutive six images of each group indicate the precision of this developed quantitation method for the micro-CT image taken at the fifth rib of each mouse.

Conclusion

Provided a quantifying method for Micro-CT images in an optimal and repeatable pulmonary fibrosis mice model for exploring novel therapeutic interventions.

CC Chemokines in Idiopathic Pulmonary Fibrosis: Pathogenic Role and Therapeutic Potential

Idiopathic pulmonary fibrosis (IPF), characterized by progressive worsening of dyspnea and irreversible decline in lung function, is a chronic and progressive respiratory disease with a poor prognosis. Chronic or repeated lung injury results in inflammation and an excessive injury-repairing response that drives the development of IPF. A number of studies have shown that the development and progression of IPF are associated with dysregulated expression of several chemokines and chemokine receptors, several of which have been used as predictors of IPF outcome. Chemokines of the CC family play significant roles in exacerbating IPF progression by immune cell attraction or fibroblast activation. Modulating levels of detrimental CC chemokines and interrupting the corresponding transduction axis by neutralizing antibodies or antagonists are potential treatment options for IPF. Here, we review the roles of different CC chemokines in the pathogenesis of IPF, and their potential use as biomarkers or therapeutic targets.

Allies or enemies? The effect of regulatory T cells and related T lymphocytes on the profibrotic environment in bleomycin-injured lung mouse models

Idiopathic pulmonary fibrosis (IPF) is characterized by permanent scarring of lung tissue and declining lung function, and is an incurable disease with increase in prevalence over the past decade. The current consensus is that aberrant wound healing following repeated injuries to the pulmonary epithelium is the most probable cause of IPF, with various immune inflammatory pathways having been reported to impact disease pathogenesis. While the role of immune cells, specifically T lymphocytes and regulatory T cells (Treg), in IPF pathogenesis has been reported and discussed recently, the pathogenic or beneficial roles of these cells in inducing or preventing lung fibrosis is still debated. This lack of understanding could be due in part to the difficulty in obtaining diseased human lung tissue for research purposes. For this reason, many animal models have been developed over the years to attempt to mimic the main clinical hallmarks of IPF: among these, inducing lung injury in rodents with the anti-cancer agent bleomycin has now become the most commonly studied animal model of IPF. Pulmonary fibrosis is the major side effect when bleomycin is administered for cancer treatment in human patients, and a similar effect can be observed after intra-tracheal administration of bleomycin to rodents. Despite many pathophysiological pathways of lung fibrosis having been investigated in bleomycin-injured animal models, one central facet still remains controversial, namely the involvement of specific T lymphocyte subsets, and in particular Treg, in disease pathogenesis. This review aims to summarize the major findings and conclusions regarding the involvement of immune cells and their receptors in the pathogenesis of IPF, and to elaborate on important parallels between animal models and the human disease. A more detailed understanding of the role of Treg and other immune cell subsets in lung injury and fibrosis derived from animal models is a critical basis for translating this knowledge to the development of new immune-based therapies for the treatment of human IPF.

Tauroursodeoxycholic acid (TUDCA) disparate pharmacological effects to lung tissue-resident memory T cells contribute to alleviated silicosis

Exposure to crystalline silica (CS) results in a persistent pulmonary inflammatory response, which results in abnormal tissue repair and excessive matrix deposition. Due to vague pathogenesis, there is virtually no practical therapeutic approach. Here we showed the pharmacological effects of TUDCA on CS-induced pulmonary inflammation and fibrosis. It also helped a faster recovery of CS-impaired pulmonary function. Mechanistically, TUDCA suppressed interferon (IFN)-γ and interleukin (IL)-17A productions by pulmonary helper T (Th) cells. We demonstrated that CS-boosted cytokine-producing Th cells were effector memory (T_EM) phenotype. TUDCA decreased the pathogenic T_EM cells expansion in the lung. Using in vivo labeling method, we discovered the T_EM cells were lung tissue residency with CD103 expression. TUDCA's anti-fibrotic effects were linked to decreasing IFN-γ producing CD103^- T_EM-like and IL-17A producing CD103⁺ T_RM-like T cells as well as restricting T_RM-like Treg cells in the lung. Specifically, TUDCA could restrain CD103⁺ T_RM-like Treg cell proliferation but not limit the CD103^- ones. Further characterization study proved that though the Tregs originally came from the thymus, the expressing levels of ST-2 were different, which provides insights into TUDCA's various effects on cell proliferation. Collectively, our data paved the way to understanding the pathogenesis of silicosis and may provide new treatments for this pulmonary fibrotic disease.

Screening and identification of potential biomarkers and therapeutic targets for systemic sclerosis-associated interstitial lung disease

Objectives

This study aims to analyze gene expression in lung tissue and lung fibroblasts of patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) to identify potential biomarkers and therapeutic targets and to examine its possible role in the pathogenesis of SSc-ILD.

Patients and methods

We obtained datasets from Gene Expression Omnibus (GEO) database, and used Robust Rank Aggregation to calculate the co-expressed differentially-expressed-genes (DEGs) in three chips, then analyzed the function, signaling pathways and the protein-protein interaction network of the DEGs. Finally, we verified the DEGs related to SSc-ILD by three databases of Comparative Toxicogenomics Database (CTD), GENE, and DisGeNET, respectively.

Results

There were 16 co-expressed DEGs related to SSc-ILD in three GEO series, of which six genes were upregulated, and 10 genes were downregulated. The CTD included 29,936 genes related to SSc, and the GENE and DisGeNET databases had 429 genes related to SSc.

Conclusion

The results of gene differential expression analysis suggest that interleukin-6, chemokine ligand 2, intercellular adhesion molecule 1, tumor necrosis factor alpha-induced protein 3, pentraxin 3, and cartilage oligomeric matrix protein may be implicated in the pathogenesis of SSc-ILD and are expected to be potential biomarkers and therapeutic targets for SSc-ILD.

Molecular Signatures of Idiopathic Pulmonary Fibrosis

Molecular patterns and pathways in idiopathic pulmonary fibrosis (IPF) have been extensively investigated, but few studies have assimilated multiomic platforms to provide an integrative understanding of molecular patterns that are relevant in IPF. Herein, we combine the coding and noncoding transcriptomes, DNA methylomes, and proteomes from IPF and healthy lung tissue to identify molecules and pathways associated with this disease. RNA sequencing, Illumina MethylationEPIC array, and liquid chromatography-mass spectrometry proteomic data were collected on lung tissue from 24 subjects with IPF and 14 control subjects. Significant differential features were identified by using linear models adjusting for age and sex, inflation, and bias when appropriate. Data Integration Analysis for Biomarker Discovery Using a Latent Component Method for Omics Studies was used for integrative multiomic analysis. We identified 4,643 differentially expressed transcripts aligning to 3,439 genes, 998 differentially abundant proteins, 2,500 differentially methylated regions, and 1,269 differentially expressed long noncoding RNAs (lncRNAs) that were significant after correcting for multiple tests (false discovery rate < 0.05). Unsupervised hierarchical clustering using 20 coding mRNA, protein, methylation, and lncRNA features with the highest loadings on the top latent variable from the four data sets demonstrates perfect separation of IPF and control lungs. Our analysis confirmed previously validated molecules and pathways known to be dysregulated in disease and implicated novel molecular features as potential drivers and modifiers of disease. For example, 4 proteins, 18 differentially methylated regions, and 10 lncRNAs were found to have strong correlations (|r| > 0.8) with MMP7 (matrix metalloproteinase 7). Therefore, by using a system biology approach, we have identified novel molecular relationships in IPF.

Mesenchymal stem cells alleviate idiopathic pneumonia syndrome by modulating T cell function through CCR2-CCL2 axis

BACKGROUND

Idiopathic pneumonia syndrome (IPS) is a non-infectious fatal complication characterized by a massive infiltration of leukocytes in lungs and diffuse pulmonary injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Conventional immunosuppressive treatments for IPS have poor therapeutic effects. Safe and effective treatments are not yet available and under explorations. Our previous study demonstrated that mesenchymal stem cells (MSCs) can alleviate IPS, but the mechanisms remain unclear.

METHODS

Co-cultured pre-activated T cells and MSCs in vitro to observe the changes in the CCR2-CCL2 axis. By establishing an IPS mouse model and administering MSCs to further verify the results of in vitro experiments.

RESULTS

Co-culture of pre-activated T cells with MSCs in vitro modulated the CCR2-CCL2 axis, resulting in quiescent T cells and polarization toward CCR2⁺CD4⁺ T cell subsets. Blocking CCR2-CCL2 interaction abolished the immunoregulatory effect of MSCs, leading to re-activation of T cells and partial reversion of polarizing toward CCR2⁺CD4⁺ T cells. In IPS mouse model, application of MSCs prolonged the survival and reduced the pathological damage and T cell infiltration into lung tissue. Activation of CCR2-CCL2 axis and production of CCR2⁺CD4⁺ T cells were observed in the lungs treated with MSCs. The prophylactic effect of MSCs on IPS was significantly attenuated by the administration of CCR2 or CCL2 antagonist in MSC-treated mice.

CONCLUSIONS

We demonstrated an important role of CCR2-CCL2 axis in modulating T cell function which is one of the mechanisms of the prophylactic effect of MSCs on IPS.

Immune dysregulation as a driver of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) affects hundreds of thousands of people worldwide, reducing their quality of life and leading to death from respiratory failure within years of diagnosis. Treatment options remain limited, with only two FDA-approved drugs available in the United States, neither of which reverse the lung damage caused by the disease or prolong the life of individuals with IPF. The only cure for IPF is lung transplantation. In this review, we discuss recent major advances in our understanding of the role of the immune system in IPF that have revealed immune dysregulation as a critical driver of disease pathophysiology. We also highlight ways in which an improved understanding of the immune system's role in IPF may enable the development of targeted immunomodulatory therapies that successfully halt or potentially even reverse lung fibrosis.

Inhibiting TGF-[Formula: see text] 1-Mediated Cellular Processes as an Effective Strategy for the Treatment of Pulmonary Fibrosis with Chinese Herbal Medicines

Pulmonary fibrosis (PF) is a chronic and irreversible interstitial lung disease that even threatens the lives of some patients infected with COVID-19. PF is a multicellular pathological process, including the initial injuries of epithelial cells, recruitment of inflammatory cells, epithelial-mesenchymal transition, activation and differentiation of fibroblasts, etc. TGF-[Formula: see text]1 acts as a key effect factor that participates in these cellular processes of PF. Recently, much attention was paid to inhibiting TGF-[Formula: see text]1 mediated cell processes in the treatment of PF with Chinese herbal medicines (CHM), an important part of traditional Chinese medicine. Here, this review first summarized the effects of TGF-[Formula: see text]1 in different cellular processes of PF. Then, this review summarized the recent research on CHM (compounds, multi-components, single medicines and prescriptions) to directly and/or indirectly inhibit TGF-[Formula: see text]1 signaling (TLRs, PPARs, micrRNA, etc.) in PF. Most of the research focused on CHM natural compounds, including but not limited to alkaloids, flavonoids, phenols and terpenes. After review, the research perspectives of CHM on TGF-[Formula: see text]1 inhibition in PF were further discussed. This review hopes that revealing the inhibiting effects of CHM on TGF-[Formula: see text]1-mediated cellular processes of PF can promote CHM to be better understood and utilized, thus transforming the therapeutic activities of CHM into practice.

Monocyte-derived dendritic cells link localized secretory IgA deficiency to adaptive immune activation in COPD

Although activation of adaptive immunity is a common pathological feature of chronic obstructive pulmonary disease (COPD), particularly during later stages of the disease, the underlying mechanisms are poorly understood. In small airways of COPD patients, we found that localized disruption of the secretory immunoglobulin A (SIgA)-containing mucosal immunobarrier correlated with lymphocyte accumulation in airway walls and development of tertiary lymphoid structures (TLS) around small airways. In SIgA-deficient mice, we observed bacterial invasion into the airway epithelial barrier with lymphocytic infiltration and TLS formation, which correlated with the progression of COPD-like pathology with advanced age. Depletion of either CD4⁺ or CD8⁺ T lymphocytes reduced the severity of emphysema in SIgA-deficient mice, indicating that adaptive immune activation contributes to progressive lung destruction. Further studies revealed that lymphocyte infiltration into the lungs of SIgA-deficient mice was dependent on monocyte-derived dendritic cells (moDCs), which were recruited through a CCR2-dependent mechanism in response to airway bacteria. Consistent with these results, we found that moDCs were increased in lungs of COPD patients, along with CD4⁺ and CD8⁺ effector memory T cells. Together, these data indicate that endogenous bacteria in SIgA-deficient airways orchestrate a persistent and pathologic T lymphocyte response through monocyte recruitment and moDC differentiation.

Recent advances targeting C-C chemokine receptor type 2 for liver diseases in monocyte/macrophage

Liver plays a critical role in metabolism, nutrient storage and detoxification. Emergency signals or appropriate immune response leads to pathological inflammation and breaks the steady state when liver dysfunction appears, which makes body more susceptible to chronic liver infection, autoimmune diseases and tumour. Compelling proof has illustrated the non-redundant importance of C-C chemokine receptor type 2 (CCR2), one of G-protein-coupled receptors, in different diseases. Selectively expressed on the surface of cells, CCR2 is involved in various signalling pathways and regulates the migration of cells. Especially, a peculiar role of CCR2 has been identified within decades in the onset and progression of hepatic diseases, which led to particular focusing on CCR2 as a new therapeutic and diagnostic target for non-alcoholic fatty liver disease and hepatocellular carcinoma. In this review, we discuss the effect of CCR2 in monocytes/macrophages on liver diseases. The application and translation of the decades of discoveries into therapies promise novel approaches in the treatment of liver disease.

Human menstrual blood-derived stem cells mitigate bleomycin-induced pulmonary fibrosis through anti-apoptosis and anti-inflammatory effects

BACKGROUND

Idiopathic pulmonary fibrosis is a kind of diffuse interstitial lung disease, the pathogenesis of which is unclear, and there is currently a lack of good treatment to improve the survival rate. Human menstrual blood-derived mesenchymal stem cells (MenSCs) have shown great potential in regenerative medicine. This study aimed to explore the therapeutic potential of MenSCs for bleomycin-induced pulmonary fibrosis.

METHODS

We investigated the transplantation of MenSCs in a pulmonary fibrosis mouse model induced by BLM. Mouse was divided into three groups: control group, BLM group, MenSC group. Twenty-one days after MenSC transplantation, we examined collagen content, pathological, fibrosis area in the lung tissue, and the level of inflammatory factors of serum. RNA sequence was used to examine the differential expressed gene between three groups. Transwell coculture experiments were further used to examine the function of MenSCs to MLE-12 cells and mouse lung fibroblasts (MLFs) in vitro.

RESULTS

We observed that transplantation of MenSCs significantly improves pulmonary fibrosis mouse through evaluations of pathological lesions, collagen deposition, and inflammation. Transwell coculturing experiments showed that MenSCs suppress the proliferation and the differentiation of MLFs and inhibit the apoptosis of MLE-12 cells. Furthermore, antibody array results demonstrated that MenSCs inhibit the apoptosis of MLE-12 cells by suppressing the expression of inflammatory-related cytokines, including RANTES, Eotaxin, GM-CSF, MIP-1γ, MCP-5, CCL1, and GITR.

CONCLUSIONS

Collectively, our results suggested MenSCs have a great potential in the treatment of pulmonary fibrosis, and cytokines revealed in antibody array are expected to become the target of future therapy of MenSCs in clinical treatment of pulmonary fibrosis.

Pharmacotherapy and adjunctive treatment for idiopathic pulmonary fibrosis (IPF)

Idiopathic pulmonary fibrosis (IPF) is an advancing and fatal lung disease with increasing incidence and prevalence. Nintedanib and pirfenidone were approved by the FDA for the treatment of IPF in 2014 based on positive phase 3 trials, and both of these antifibrotic drugs are conditionally recommended in the 2015 ATS/ERS/JRS/ALAT Clinical Practice Guideline. Although an improvement over previously suggested therapies, their capacity to reduce, but not completely arrest or improve, lung function over time presents an opportunity for novel or add-on pharmacologic agents. The purpose of this review is to deliver a brief overview of the results of phase 3/4 IPF trials with pirfenidone and nintedanib, as well as highlight encouraging results of phase 1/2 trials with novel therapies. Long-term studies indicate that pirfenidone and nintedanib are effective IPF treatments, with acceptable safety and tolerability. The combination of pirfenidone and nintedanib appear safe. Promising results have recently been made public for several phase 2 trials with novel targets, including the autotaxin-lysophosphatidic acid (ATX/LPA) pathway, connective tissue growth factor (CTGF), pentraxin-2, G protein-coupled receptor agonists/antagonists, αvβ6 integrin, and galectin-3. Results of treatments directed at gastro-esophageal reflux in patients with IPF have also been published. Currently, monotherapy with pirfenidone or nintedanib is the mainstay of pharmacological treatment for IPF. Innovative therapies along with combinations of pharmacological agents hold great promise for the future.

Biomarkers in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, debilitating, fibrotic lung disease leading to respiratory failure and ultimately to death. Being the prototype of interstitial lung diseases, IPF is characterized by marked heterogeneity regarding its clinical course. Despite significant progress in the understanding of its pathogenesis, we still cannot reliably predict the course of the disease and the response to treatment of an individual patient. Non-invasive biomarkers, in particular serum biomarkers, for the (early) diagnosis, differential diagnosis, prognosis and prediction of therapeutic response are urgently needed. Numerous molecules involved in alveolar epithelial cell injury, fibroproliferation and matrix remodeling as well as immune regulation have been proposed as potential biomarkers. Furthermore, genetic variants of TOLLIP, MUC5B, and other genes are associated with a differential response to treatment and with the development and/or the prognosis of IPF. Additionally, the bacterial signature in IPF lungs, as shown from microbiome analyses, as well as mitochondrial DNA seem to have promising roles as biomarkers. Moreover, combination of multiple biomarkers may identify comprehensive biomarker signatures in IPF patients. However, there is still a long way until these potential biomarkers complete or substitute for the clinical and functional parameters currently available for IPF.