Role of IL-17 family cytokines in the progression of IPF from inflammation to fibrosis

A bioinformatics approach combined with experimental validation analyzes the efficacy of azithromycin in treating SARS-CoV-2 infection in patients with IPF and COPD These authors contributed equally: Yining Xie, Guangshu Chen, and Weiling Wu

The swift transmission rate and unfavorable prognosis associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have prompted the pursuit of more effective therapeutic interventions. Azithromycin (AZM) has garnered significant attention for its distinctive pharmacological mechanisms in the treatment of SARS-CoV-2. This study aims to elucidate the biological rationale for employing AZM in patients with chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) who are infected with SARS-CoV-2. Genetic data about COVID-19, COPD, and IPF were independently obtained from the GeneCards database. And 40 drug targets about AZM were retrieved from the STITCH database. The analysis revealed that 311 DEGs were common among COPD, IPF, and COVID-19, and we further found eight genes that interacted with AZM targets. We conducted an analysis of hub genes and their corresponding signaling pathways in these patient cohorts. Additionally, we explored the inhibitory effects of AZM on these hub genes. AZM demonstrated a significant inhibitory effect on eight key genes, except for AR and IL-17 A. These findings suggest that AZM may serve as a promising therapeutic agent for patients with COPD and IPF and SARS-CoV-2 infection.

Immune Dysregulation in HIV and COVID-19 Co-infection: Therapeutic Implications

BACKGROUND

Co-infection with HIV and SARS-CoV-2 presents a complex clinical picture. Deciphering the immune response in this population, particularly the role of cytokines underlying immunopathogenesis could elucidates the development of targeted therapeutic interventions.

METHODS

This prospective, two-stage study enrolled 75 individuals with HIV diagnosed with COVID-19 (case group) and 25 individuals from the general population infected with SARS-CoV-2 only (control group). COVID-19 diagnosis followed World Health Organization guidelines. Plasma cytokine levels were measured using a cytokine bead array.

RESULTS

The case group skewed slightly females (61.2% vs. 42.9% female in the control group) an average age of 3 years older (44.13 years vs. 40.86 years). Importantly, all the case group participants had mild complications, while a significant majority (88.1%) in the control group experienced severe complications. The control group displayed a substantially higher IgM titer 963 IU/mL compared to only 39.3 IU/mL in the case group. The control group had significantly higher levels of IL-6, IL-10, IFN-γ, TNF-α compared to the case group.

CONCLUSION

This study suggests a potentially distinct immune response in HIV-positive patients when infected with SARS-CoV-2. Elucidating these differences could lead to the development of more effective treatment strategies for this vulnerable population.

CD103+ dendritic cell-fibroblast crosstalk via TLR9, TDO2, and AHR signaling drives lung fibrogenesis

Idiopathic pulmonary fibrosis (IPF) is characterized by progressive scarring and loss of lung function. With limited treatment options, patients die from the disease within 2-5 years. The molecular pathogenesis underlying the immunologic changes that occur in IPF is poorly understood. We characterize noncanonical aryl-hydrocarbon receptor (ncAHR) signaling in DCs as playing a role in the production of IL-6 and increased IL-17+ cells, promoting fibrosis. TLR9 signaling in myofibroblasts is shown to regulate production of TDO2, which converts tryptophan into the endogenous AHR ligand kynurenine. Mice with augmented ncAHR signaling were created by crossing mice harboring a floxed AHR exon 2 deletion (AHRΔex2) with mice harboring a CD11c-Cre. Bleomycin (blm) was used to study fibrotic pathogenesis. Isolated CD11c+ cells and primary fibroblasts were treated ex vivo with relevant TLR agonists and AHR-modulating compounds to study how AHR signaling influenced inflammatory cytokine production. Human datasets were also interrogated. Inhibition of all AHR signaling rescued fibrosis; however, AHRΔex2 mice treated with blm developed more fibrosis, and DCs from these mice were hyperinflammatory and profibrotic upon adoptive transfer. Treatment of fibrotic fibroblasts with TLR9 agonist increased expression of TDO2, and fibrotic fibroblasts activated IL-6 production in CD103+ DCs. Study of human samples corroborated the relevance of these findings in patients with IPF. We also show, for the first time to our knowledge, that AHR exon 2 floxed mice retain the capacity for ncAHR signaling.

Advances in understanding the role of interleukins in pulmonary fibrosis (Review)

Pulmonary fibrosis (PF) is a progressive, irreversible disease characterized by heterogeneous interstitial lung tissue damage. It originates from persistent or repeated lung epithelial injury and leads to the activation and differentiation of fibroblasts into myofibroblasts. Interleukins (ILs) are a group of lymphokines crucial for immunomodulation that are implicated in the pathogenesis of PF. However, different types of ILs exert disparate effects on PF. In the present review, based on the effect on PF, ILs are classified into three categories: i) Promotors of PF; ii) inhibitors of PF; and iii) those that exert dual effects on PF. Several types of ILs can promote PF by provoking inflammation, initiating proliferation and transdifferentiation of epithelial cells, exacerbating lung injury, while other ILs can inhibit PF through suppressing expression of inflammatory factors, modulating the Th1/Th2 balance and autophagy. The present review summarizes the association of ILs and PF, focusing on the roles and mechanisms of ILs underlying PF.

Silicone breast implant-associated pathologies and T cell-mediated responses

Silicone breast implants elicit a foreign body response (FBR) defined by a complex cascade of various immune cells. Studies have shown that the capsule around silicone breast implants that forms as a result of the FBR contains large T cell populations. T cells are implicated in pathologies such as capsular contracture, which is defined by an excessively fibrotic capsule, and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), a non-Hodgkin's lymphoma. In this article, we provide a synthesis of 17 studies reporting on T cell-mediated responses to silicone breast implants and highlight recent developments on this topic. The lymphocytes present in the breast implant capsule are predominantly Th1 and Th17 cells. Patients with advanced capsular contracture had fewer T-regulatory (Treg) cells present in the capsules that were less able to suppress T effector cells such as Th17 cells, which can promote fibrosis in autoimmune conditions. Textured silicone implants, which are associated with BIA-ALCL, created a more robust T cell response, especially CD30 + T cells in the peri-implant fluid and CD4 + T cells in the capsule. Cultivating a deeper understanding of T cell-mediated responses to silicone breast implants may allow for novel treatments of breast implant-associated complications and malignancies.

Distinct therapeutic effects of auraptene and umbelliprenin on TNF-α and IL-17 levels in a murine model of chronic inflammation

Objective

To compare the anti-arthritic potential of orally administered auraptene (AUR) and umbellliprenin (UMB) in chronic inflammation by exploring the differential effect on regulating TNF-α and IL-17.

Methods & materials

Sixty male rats were divided into ten groups, and after confirming chronic inflammation, the treatment groups received AUR or UMB orally for 9 days. On day 16, histopathological changes were evaluated. Altered serum levels of the inflammatory cytokines TNF-α and IL-17 were examined as the underlying mechanisms.

Results

Administering AUR orally at 16 mM/kg caused a significant increase in body weight gain compared to the baseline (p < 0.05), while UMB at a dose of 64 mM/kg significantly reduced edema size (p < 0.01). TNF-α levels were significantly lower in all doses of AUR and UMB treatments compared to the arthritis control group (p < 0.05). Treatment with AUR at all relative doses resulted in a significant decrease in IL-17 levels compared to the arthritis control group (p < 0.05), whereas UMB treatment did not show a significant effect on IL-17 levels.

Conclusion

AUR and UMB regulate TNF-α and IL-17 differently; AUR inhibits both, showing broad therapeutic potential, while UMB specifically targets TNF-α, showing a specialized role.

Spatio-temporal expression of Sox2+ progenitor cells regulates the regeneration of rat submandibular gland

OBJECTIVE

Sox2 plays crucial roles in tissues homeostasis and regeneration. However, there are lack of a comprehensive examination of Sox2 expression and its functional role in submandibular gland regeneration. Therefore, we aimed to elucidate the impact of Sox2 on submandibular gland regeneration.

MATERIALS AND METHODS

A Sprague-Dawley rat submandibular gland duct ligation/de-ligation regeneration model was conducted in this study. Sox2-shRNA vectors were retro-ductally administered into the submandibular gland to establish a stable Sox2 knockdown model. Conventional histopathological and molecular biological methods were used to investigate phenotypic changes.

RESULTS

The submandibular gland normalized completely 28 days after ligature removal (following 7 days of duct ligation). AQP5 expression gradually increased after ligation removal until returning to normal levels. In submandibular gland regeneration, Sox2 re-expressed and co-expressed with AQP5+ acinar cells, and Sox2 expression peaked on day 14, recovered to normal on day 28, reproducing the developmental pattern. Sox2 knockdown hindered gland regeneration and induced irreversible fibrosis. The AQP5 expression was significantly lower than the contemporaneous solely ligated group, while the blue collagen deposition and the Vimentin expression increased prominently. The expression of CD68, IL-1β, TNF-α and IL-17A increased significantly, and epithelial cells in the Sox2 knockdown group expressed higher levels of IL-17A.

CONCLUSIONS

These findings highlight Sox2 as a crucial regulator of the acinar cell lineage. Sox2+ progenitor cells are pivotal for acinar cell maintenance, which is indispensable for submandibular gland regeneration. Collectively, our findings may help develop targeted interventions for enhancing tissue repair and preventing irreversible fibrosis in salivary gland disorders.

IL-17A-Induced Redox Imbalance and Inflammatory Responses in Mice Lung via Act1-TRAF6-IKBα Signaling Pathway: Implications for Lung Disease Pathogenesis

IL-17A is a potent proinflammatory cytokine that plays a crucial role in the pathogenesis of various lung diseases. This study focused on the evaluation of the role of IL-17 receptor signaling through one-week intranasal exposure of IL-17A in lung tissues of BALB/c mice. IL-17A triggered inflammatory responses in the mice lungs and led to changes in the morphological alveolar arrangements. Exposure of IL-17A induced redox imbalance by triggering an increase in the level of the pro-oxidants (reactive oxygen species, nitrite and malondialdehyde) and reduction of the levels of antioxidant proteins (glutathione, superoxide dismutase and catalase) in the lung tissue. IL-17A also caused a significant elevation in the levels of proinflammatory cytokines lines including TNF-α, IL-1β and IL-6, in lung tissue as well as in plasma. More interestingly, these changes were accompanied by the alterations in IL-17 receptor downstream signaling through activation of IL-17R-Act1-TRAF6-IKBα-mediated pathway. IL-17A exposure also caused lung tissue injury, recruitment and polarization of immune cells from anti-inflammatory to pro-inflammatory. This study clearly demonstrated the role of IL-17A-induced signaling in worsening lung inflammatory diseases, and hence points towards its emergence as an important therapeutic target to control lung inflammation.

The role of epithelial-mesenchymal transition in pulmonary fibrosis: lessons from idiopathic pulmonary fibrosis and COVID-19

Despite the tremendous advancements in the knowledge of the pathophysiology and clinical aspects of SARS-CoV-2 infection, still many issues remain unanswered, especially in the long-term effects. Mounting evidence suggests that pulmonary fibrosis (PF) is one of the most severe complications associated with COVID-19. Therefore, understanding the molecular mechanisms behind its development is helpful to develop successful therapeutic strategies. Epithelial to mesenchymal transition (EMT) and its cell specific variants endothelial to mesenchymal transition (EndMT) and mesothelial to mesenchymal transition (MMT) are physio-pathologic cellular reprogramming processes induced by several infectious, inflammatory and biomechanical stimuli. Cells undergoing EMT acquire invasive, profibrogenic and proinflammatory activities by secreting several extracellular mediators. Their activity has been implicated in the pathogenesis of PF in a variety of lung disorders, including idiopathic pulmonary fibrosis (IPF) and COVID-19. Aim of this article is to provide an updated survey of the cellular and molecular mechanisms, with emphasis on EMT-related processes, implicated in the genesis of PF in IFP and COVID-19.

The mechanism of cytokine regulation of cancer occurrence and development in the tumor microenvironment and its application in cancer treatment: a narrative review

Background and Objective

The occurrence and development of tumors in human tissues widely depend on their surrounding environment, known as the tumor microenvironment (TME), which comprises various cells, molecules, and blood vessels. Through modifications, organization, and integration, these elements serve as potential therapeutic targets in anti-cancer therapy, supporting and promoting the proliferation, invasion, and metabolism of tumor cells. Cytokines within TME are responsible for immune cell activation, proliferation, and differentiation, thereby influencing the tumor's behavior. This article reviews the use of cytokines in tumor immunotherapy and combs the network signals that cytokines mediate in the development of malignancies.

Methods

A literature search of international sources was carried out on the PubMed and Web of Science databases, using main keywords such as "tumor immunotherapy", "cytokines", "chemokines", "tumor microenvironment", "recombinant cytokine engineering", and "tumor necrosis factor superfamily".

Key Content and Findings

The review provides a thorough summary of the functions of tumor necrosis factor superfamilies, chemokines, and interleukins within the TME as well as their therapeutic uses. Their potential as novel targets for tumor treatment is also evaluated. Furthermore, this paper focuses on various feasible strategies for recombinant cytokines reported in recent years, especially the cytokine engineering methods for targeting tumors. Ultimately, this paper contributes to an enhanced understanding among researchers of the mechanisms underlying the impact of the TME on disease development, thereby laying a solid foundation for the future development of new tumor therapies based on cytokines within the TME.

Conclusions

Cytokine immunotherapy holds promise on antitumor therapy. It is anticipated that the effectiveness of tumor treatment and the quality of life for tumor patients will continue to improve with ongoing research and development in this field.

Altered expression pattern of immune response-related genes and isoforms in hypersensitivity pneumonitis lung fibroblasts

Hypersensitivity pneumonitis (HP) is an immune-mediated inflammatory interstitial lung disease that may evolve to pulmonary fibrosis, a progressive disorder with a poor prognosis characterized by fibroblast activation and extracellular matrix accumulation. In HP lung fibroblasts, the gene expression of proteins involved in the interaction with the immune response, their isoforms, and how they influence their phenotype have yet to be elucidated. We analyzed the expression and splicing variants of 16 target genes involved in the interaction between HP fibroblasts and immune signaling and evaluated possible correlations with clinical data. The comparison of HP and control fibroblasts revealed distinct gene expression patterns. HP lung fibroblasts displayed an increased expression of IFI27 and PDFGRA and a downregulation of IL17RC and TGFBR3. IFI27 immunoreactive protein was markedly increased in HP lung tissues and normal fibroblasts treated with TGF-β. Furthermore, IFI27 overexpression in normal fibroblasts increased α-SMA and decreased cell number over time. The isoform analysis showed similar expression patterns for most genes, except for the AGER receptor with increased soluble variants relative to full-length AGER in HP fibroblasts. These findings indicate important differences in the expression of genes related to the immune response by HP fibroblasts, highlighting their unique characteristics and providing further insight into a possible profibrotic role of IFI27 in the disease.

The role of IL-17 and Th17 cells in keloid pathogenesis

Keloids are characterized histologically by excessive fibroblast proliferation and connective tissue deposition, and clinically by scar tissue extending beyond the original site of skin injury. These scars can cause pruritus, pain, physical disfigurement, anxiety, and depression. As a result, keloid patients often have a diminished quality of life with a disproportionate burden on ethnic minorities. Despite advances in understanding keloid pathology, there is no effective Food and Drug Administration (FDA)-approved pharmacotherapy. Recent studies have highlighted the possible pathologic role of T helper (Th)17 cells and interleukin (IL)-17 in keloid formation, as well as their implication in other inflammatory disorders. This systematic review characterizes the role of Th17 cells and IL-17 in keloid pathogenesis, highlighting this pathway as a potential therapeutic target. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search on PubMed, Embase, MEDLINE, and Web of Science databases on June 5, 2024. The search included terms related to Th17 cells, IL-17, and keloids. Thirteen studies met the inclusion criteria, comprising basic science and bioinformatic studies focusing on Th17 cells and IL-17. Key findings include increased Th17 cell infiltration and IL-17 expression in keloids, IL-17's role in amplifying the inflammatory and fibrotic response via the promotion of IL-6 expression, and IL-17's involvement in upregulating fibrotic markers via SDF-1 and HIF-1α pathways. IL-17 also activates the transforming growth factor beta (TGF-β)/Smad pathway in keloid fibroblasts. Th17 cells and IL-17 significantly contribute to the inflammatory and fibrotic processes in keloid pathogenesis. Therefore, targeting the IL-17 pathway offers a potential new therapeutic target to improve keloid patients' outcomes. Future research could further elucidate the role of Th17 cells and IL-17 in keloid pathogenesis and assess the safety and efficacy of targeting this pathway in human studies.

Pancreatic stellate cells and the interleukin family: Linking fibrosis and immunity to pancreatic ductal adenocarcinoma (Review)

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive form of cancer with a low survival rate. A successful treatment strategy should not be limited to targeting cancer cells alone, but should adopt a more comprehensive approach, taking into account other influential factors. These include the extracellular matrix (ECM) and immune microenvironment, both of which are integral components of the tumor microenvironment. The present review describes the roles of pancreatic stellate cells, differentiated cancer‑associated fibroblasts and the interleukin family, either independently or in combination, in the progression of precursor lesions in pancreatic intraepithelial neoplasia and PDAC. These elements contribute to ECM deposition and immunosuppression in PDAC. Therapeutic strategies that integrate interleukin and/or stromal blockade for PDAC immunomodulation and fibrogenesis have yielded inconsistent results. A deeper comprehension of the intricate interplay between fibrosis, and immune responses could pave the way for more effective treatment targets, by elucidating the mechanisms and causes of ECM fibrosis during PDAC progression.

Investigation of pulmonary inflammatory responses following intratracheal instillation of and inhalation exposure to polypropylene microplastics

BACKGROUND

Microplastics have been detected in the atmosphere as well as in the ocean, and there is concern about their biological effects in the lungs. We conducted a short-term inhalation exposure and intratracheal instillation using rats to evaluate lung disorders related to microplastics. We conducted an inhalation exposure of polypropylene fine powder at a low concentration of 2 mg/m3 and a high concentration of 10 mg/m3 on 8-week-old male Fischer 344 rats for 6 h a day, 5 days a week for 4 weeks. We also conducted an intratracheal instillation of polypropylene at a low dose of 0.2 mg/rat and a high dose of 1.0 mg/rat on 12-week-old male Fischer 344 rats. Rats were dissected from 3 days to 6 months after both exposures, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected to analyze lung inflammation and lung injury.

RESULTS

Both exposures to polypropylene induced a persistent influx of inflammatory cells and expression of CINC-1, CINC-2, and MPO in BALF from 1 month after exposure. Genetic analysis showed a significant increase in inflammation-related factors for up to 6 months. The low concentration in the inhalation exposure of polypropylene also induced mild lung inflammation.

CONCLUSION

These findings suggest that inhaled polypropylene, which is a microplastic, induces persistent lung inflammation and has the potential for lung disorder. Exposure to 2 mg/m3 induced inflammatory changes and was thought to be the Lowest Observed Adverse Effect Level (LOAEL) for acute effects of polypropylene. However, considering the concentration of microplastics in a real general environment, the risk of environmental hazards to humans may be low.

Prognostic model of fibroblasts in idiopathic pulmonary fibrosis by combined bulk and single-cell RNA-sequencing

Background

Fibroblasts play an important role in the development of idiopathic pulmonary fibrosis (IPF).

Methods

We employed single-cell RNA-sequencing data obtained from the Gene Expression Omnibus database to perform cell clustering and annotation analyses. We then performed secondary clustering of fibroblasts and conducted functional enrichment and cell trajectory analyses of the two newly defined fibroblast subtypes. Bulk RNA-sequencing data were used to perform consensus clustering and weighted gene co-expression network analysis. We constructed a fibroblast-related prognostic model using least absolute shrinkage, selection operator regression, and Cox regression analysis. The prognostic model was validated using a validation dataset. Immune infiltration and functional enrichment analyses were conducted for patients in the high- and low-risk IPF groups.

Results

We characterized two fibroblast subtypes that are active in IPF (F3+ and ROBO2+). Using fibroblast-related genes, we identified five genes (CXCL14, TM4SF1, CYTL1, SOD3, and MMP10) for the prognostic model. The area under the curve values of our prognostic model were 0.852, 0.859, and 0.844 at one, two, and three years in the training set, and 0.837, 0.758, and 0.821 at one, two, and three years in the validation set, respectively.

Conclusion

This study annotates and characterizes different subtypes of fibroblasts in IPF.

Integrating network pharmacology, experimental validation and molecular docking to reveal the alleviation of Yinhuang granule on idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by the abnormal proliferation of fibroblast and excessive deposition of extracellular matrix (ECM), accompanied by inflammation and ultimately respiratory failure. Yinhuang granule (YHG), with clinical properties of clearing heat, detoxifying and anti-inflammation, is commonly used to heal upper respiratory diseases in China for decades.

PURPOSE

To explore the improvement of YHG on bleomycin (BLM)-induced IPF in mice and its possible engaged mechanism.

METHODS

The mortality rate was recorded, lung function was determined and hematoxylin-eosin (H&E) staining was carried out to explore the alleviation of YHG on BLM-caused IPF in mice. Hydroxyproline, collagen I and collagen III contents were detected, and Sirius red and Masson staining were conducted to evaluate YHG's alleviation on lung fibrosis. The underlying mechanism was predicted by network pharmacology, and confirmed by Real-time polymerase chain reaction (RT-PCR), Western-blot (WB) and enzyme linked immunosorbent assay (ELISA). The binding affinity between related key proteins and active compounds in YHG was calculated by using molecular docking, and further validated by cellular thermal shift assay (CESTA).

RESULTS

YHG (400, 800 mg/kg) weakened lung damage and pulmonary fibrosis in mice induced by BLM. Network pharmacology and experimental validation displayed that inflammation and angiogenesis participated in the YHG-provided improvement on IPF, and key involved molecules included tumor necrosis factor-α (TNFα), vascular endothelial growth factor-A (VEGFA), interleukine-6 (IL-6), etc. The data of molecular docking presented that some main active compounds from YHG had a high binding affinity with TNFR1 or VEGFR2, and some of them were further validated by CESTA.

CONCLUSION

YHG effectively improved the BLM-induced IPF in mice via reducing inflammation and angiogenesis.

IL-17 in wound repair: bridging acute and chronic responses

Chronic wounds, resulting from persistent inflammation, can trigger a cascade of detrimental effects including exacerbating inflammatory cytokines, compromised blood circulation at the wound site, elevation of white blood cell count, increased reactive oxygen species, and the potential risk of bacterial infection. The interleukin-17 (IL-17) signaling pathway, which plays a crucial role in regulating immune responses, has been identified as a promising target for treating inflammatory skin diseases. This review aims to delve deeper into the potential pathological role and molecular mechanisms of the IL-17 family and its pathways in wound repair. The intricate interactions between IL-17 and other cytokines will be discussed in detail, along with the activation of various signaling pathways, to provide a comprehensive understanding of IL-17's involvement in chronic wound inflammation and repair.

Efficacy and safety of bimekizumab in the treatment of psoriatic arthritis: a systematic review and meta-analysis

BACKGROUND

Bimekizumab, a humanized monoclonal IgG1 antibody targeting both interleukin (IL)-17A and IL-17F, could be effective for treating Psoriatic arthritis (PsA). This study aimed to systematically evaluate the efficacy and safety of bimekizumab in the management of PsA.

RESEARCH DESIGN AND METHODS

A comprehensive literature search by August 2023 was performed through PubMed, Embase, Cochrane Controlled Register of Trials, and ClinicalTrials.gov. investigating the efficacy or safety data of bimekizumab in the treatment of PsA. Data was pooled using the random-effects models. Egger tests were used to evaluate potential publication bias.

RESULTS

A total of 4 RCTs, involving 892 PsA patients and 467 placebo controls, were included in this analysis. Bimekizumab significantly increased the rates of PASI75 and PASI100 compared with placebos [RR = 7.22, 95% CI (5.24, 9.94), p < 0.001; RR = 10.12, 95% CI (6.00, 17.09), p < 0.001]. The rate of overall adverse events was slightly higher in the bimekizumab group [RR = 1.42, 95% CI (1.05, 1.93) p = 0.023). However, there were fewer adverse severe drug reactions in the bimekizumab group compared to the placebo.

CONCLUSION

Bimekizumab had a significant clinical benefit in managing PsA and an acceptable safety profile.

Identification and validation of CCR5 linking keloid with atopic dermatitis through comprehensive bioinformatics analysis and machine learning

There is sufficient evidence indicating that keloid is strongly associated with atopic dermatitis (AD) across ethnic groups. However, the molecular mechanism underlying the association is not fully understood. The aim of this study is to discover the underlying mechanism of the association between keloid and AD by integrating comprehensive bioinformatics techniques and machine learning methods. The gene expression profiles of keloid and AD were downloaded from the Gene Expression Omnibus (GEO) database. A total of 449 differentially expressed genes (DEGs) were found to be shared in keloid and AD using the training datasets of GEO (GSE158395 and GSE121212). The hub genes were identified using the protein-protein interaction network and Cytoscape software. 20 of the most significant hub genes were selected, which were mainly involved in the regulation of the inflammatory and immune response. Through two machine learning algorithms of LASSO and SVM-RFE, CCR5 was identified as the most important key gene. Subsequently, upregulated CCR5 gene expression was confirmed in validation GEO datasets (GSE188952 and GSE32924) and clinical samples of keloid and AD. Immune infiltration analysis showed that T helper (Th) 1, 2 and 17 cells were significantly enriched in the microenvironment of both keloid and AD. Positive correlations were found between CCR5 and Th1, Th2 and Th17 cells. Finally, two TFs of CCR5, NR3C2 and YY1, were identified, both of which were downregulated in keloid and AD tissues. Our study firstly reveals that keloid and AD shared common inflammatory and immune pathways. Moreover, CCR5 plays a key role in the pathogenesis association between keloid and AD. The common pathways and key genes may shed light on further mechanism research and targeted therapy, and may provide therapeutic interventions of keloid with AD.

Psoriasis may increase the risk of idiopathic pulmonary fibrosis: a two-sample Mendelian randomization study

BACKGROUND

Although some studies have indicated that Psoriasis could contribute to the risk of idiopathic pulmonary fibrosis (IPF), no study has reported a clear causal association between them. Our aim was to explore the potential relationship between Psoriasis and IPF using Mendelian randomization (MR) design.

METHODS

To explore a causal association between Psoriasis and IPF, we used genetic instruments from the largest available genome-wide association study (GWAS) of European ancestry, including psoriasis (5314 cases, 457,619 controls) and IPF (1028 cases, 196,986 controls). Our main analyses were conducted by inverse-variance weighted (IVW) method with random-effects model, with the other complementary four analyses: weighted median method, weighted mode, multivariable MR and MR-Egger approach.

RESULTS

The results of IVW methods demonstrated that genetically predicted psoriasis was significantly associated with higher odds of IPF, with an odds ratio (OR) of 1.09 (95%CI, 1.01-1.18; P = 0.02). Weighted median method, weighted mode and multivariable MR also demonstrated directionally similar results (P < 0.05), while the MR-Egger regression did not reveal the impact of psoriasis on IPF (OR = 1.09, 95%CI, 0.98-1.21; P = 0.11). In addition, both funnel plots and MR-Egger intercepts indicated no directional pleiotropic effects between psoriasis and IPF.

CONCLUSIONS

Our study provided potential evidence between genetically predicted psoriasis and IPF, which suggests that understanding the mutual risk factors between psoriasis and IPF can facilitate the clinical management of both diseases.

IL-17A deficiency inhibits lung cancer-induced osteoclastogenesis by promoting apoptosis of osteoclast precursor cells

Osteoclasts are crucial in the events leading to bone metastasis of lung cancer. Interleukin-17A (IL-17A) affects osteogenesis by regulating the survival of osteoclast precursors (OCPs) and is enriched in lung cancer cells. However, how factors derived from tumor cells that metastasize to bone affect osteoclastogenesis remains poorly understood. We examined whether IL-17A derived from lung cancer cells affects osteoclast differentiation by regulating OCP apoptosis. IL-17A expression was inhibited in A549 non-small cell lung cancer cells using RNA interference. Compared with conditioned medium (CM) from A549 cells (A549-CM), CM from IL-17A-deficient A549 cells (A549-si-CM) suppressed osteoclastogenesis. The mRNA expression of osteoclast-specific genes was downregulated following A549-si-CM treatment. Furthermore, A549-si-CM promoted osteoclast precursor apoptosis at an early stage of osteoclastogenesis, which was related to the promotion of caspase-3 expression by A549-si-CM during osteoclast differentiation. In vivo experiments also showed that inhibition of IL-17A expression in A549 cells reduced osteoclast activation and bone tissue destruction. Collectively, our results indicate that IL-17A deficiency inhibits lung cancer-induced osteoclast differentiation by promoting apoptosis of osteoclast precursors in the early stage of osteoclast formation and that IL-17A is a potential therapeutic target for cancer-associated bone resorption in patients with lung cancer.

Deciphering the fibrotic process: mechanism of chronic radiation skin injury fibrosis

This review explores the mechanisms of chronic radiation-induced skin injury fibrosis, focusing on the transition from acute radiation damage to a chronic fibrotic state. It reviewed the cellular and molecular responses of the skin to radiation, highlighting the role of myofibroblasts and the significant impact of Transforming Growth Factor-beta (TGF-β) in promoting fibroblast-to-myofibroblast transformation. The review delves into the epigenetic regulation of fibrotic gene expression, the contribution of extracellular matrix proteins to the fibrotic microenvironment, and the regulation of the immune system in the context of fibrosis. Additionally, it discusses the potential of biomaterials and artificial intelligence in medical research to advance the understanding and treatment of radiation-induced skin fibrosis, suggesting future directions involving bioinformatics and personalized therapeutic strategies to enhance patient quality of life.

SGK1 aggravates idiopathic pulmonary fibrosis by triggering H3k27ac-mediated macrophage reprogramming and disturbing immune homeostasis

Idiopathic pulmonary fibrosis (IPF) is characterized by fibrotic matrix deposition and irreversible aberrant tissue remodeling. Their mechanisms of action are associated with the activation of macrophages and a disturbed immune environment. We aim to determine how these activated macrophages influenced the pathogenesis of pulmonary fibrosis. We found the fibrotic areas of IPF patients contained more serum and glucocorticoid-induced kinase 1 (SGK1)-positive and M2-type macrophages. Similarly, bleomycin (BLM)+LPS significantly triggered high expression of SGK1 in the IPF mice, accompanied by destroyed lung structure and function, increased fibrosis markers and disturbed immune microenvironment. Mechanistically, SGK1 markedly promoted the reprogramming of M2-type macrophages in fibrotic lungs by triggering glycogen synthase kinase 3beta (GSK3β)-tat-interacting protein 60 (TIP60)- histone-3 lysine-27 acetylation (H3K27ac) signalings, which further released chemokine (C-C motif) ligand 9 (CCL9) to attract Th17 cells and delivered TGF-β to fibroblasts for synergistically destroying immune microenvironment, which was largely reversed by macrophage depletion in mice. We took macrophages as the entry point to deeply analyze IPF pathogenesis and further provided insights for the development of novel drugs represented by SGK1.

Targeting Interleukin-17 as a Novel Treatment Option for Fibrotic Diseases

Fibrosis is the end result of persistent inflammatory responses induced by a variety of stimuli, including chronic infections, autoimmune reactions, and tissue injury. Fibrotic diseases affect all vital organs and are characterized by a high rate of morbidity and mortality in the developed world. Until recently, there were no approved antifibrotic therapies. In recent years, high levels of interleukin-17 (IL-17) have been associated with chronic inflammatory diseases with fibrotic complications that culminate in organ failure. In this review, we provide an update on the role of IL-17 in fibrotic diseases, with particular attention to the most recent lines of research in the therapeutic field represented by the epigenetic mechanisms that control IL-17 levels in fibrosis. A better knowledge of the IL-17 signaling pathway implications in fibrosis could design new strategies for therapeutic benefits.

Targeting GPR65 alleviates hepatic inflammation and fibrosis by suppressing the JNK and NF-κB pathways

BACKGROUND

G-protein coupled receptors (GPCRs) are recognized as attractive targets for drug therapy. However, it remains poorly understood how GPCRs, except for a few chemokine receptors, regulate the progression of liver fibrosis. Here, we aimed to reveal the role of GPR65, a proton-sensing receptor, in liver fibrosis and to elucidate the underlying mechanism.

METHODS

The expression level of GPR65 was evaluated in both human and mouse fibrotic livers. Furthermore, Gpr65-deficient mice were treated with either bile duct ligation (BDL) for 21 d or carbon tetrachloride (CCl4) for 8 weeks to investigate the role of GPR65 in liver fibrosis. A combination of experimental approaches, including Western blotting, quantitative real-time reverse transcription‑polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA), confocal microscopy and rescue studies, were used to explore the underlying mechanisms of GPR65's action in liver fibrosis. Additionally, the therapeutic potential of GPR65 inhibitor in the development of liver fibrosis was investigated.

RESULTS

We found that hepatic macrophages (HMs)-enriched GPR65 was upregulated in both human and mouse fibrotic livers. Moreover, knockout of Gpr65 significantly alleviated BDL- and CCl4-induced liver inflammation, injury and fibrosis in vivo, and mouse bone marrow transplantation (BMT) experiments further demonstrated that the protective effect of Gpr65 knockout is primarily mediated by bone marrow-derived macrophages (BMMs). Additionally, in vitro data demonstrated that Gpr65 silencing and GPR65 antagonist inhibited, while GPR65 overexpression and application of GPR65 endogenous and exogenous agonists enhanced the expression and release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and transforming growth factor-β (TGF-β), all of which subsequently promoted the activation of hepatic stellate cells (HSCs) and the damage of hepatocytes (HCs). Mechanistically, GPR65 overexpression, the acidic pH and GPR65 exogenous agonist induced up-regulation of TNF-α and IL-6 via the Gαq-Ca2+-JNK/NF-κB pathways, while promoted the expression of TGF-β through the Gαq-Ca2+-MLK3-MKK7-JNK pathway. Notably, pharmacological GPR65 inhibition retarded the development of inflammation, HCs injury and fibrosis in vivo.

CONCLUSIONS

GPR65 is a major regulator that modulates the progression of liver fibrosis. Thus, targeting GPR65 could be an effective therapeutic strategy for the prevention of liver fibrosis.

Acute lung injury caused by sepsis: how does it happen?

Sepsis is a systemic inflammatory disease caused by severe infections that involves multiple systemic organs, among which the lung is the most susceptible, leaving patients highly vulnerable to acute lung injury (ALI). Refractory hypoxemia and respiratory distress are classic clinical symptoms of ALI caused by sepsis, which has a mortality rate of 40%. Despite the extensive research on the mechanisms of ALI caused by sepsis, the exact pathological process is not fully understood. This article reviews the research advances in the pathogenesis of ALI caused by sepsis by focusing on the treatment regimens adopted in clinical practice for the corresponding molecular mechanisms. This review can not only contribute to theories on the pathogenesis of ALI caused by sepsis, but also recommend new treatment strategies for related injuries.

Stevioside attenuates bleomycin-induced pulmonary fibrosis by activating the Nrf2 pathway and inhibiting the NF-κB and TGF-β1/Smad2/3 pathways

Objective: This study aimed to investigate the effects of stevioside (STE) on pulmonary fibrosis (PF) and the potential mechanisms. Methods: In this study, a mouse model of PF was established by a single intratracheal injection of bleomycin (BLM, 3 mg/kg). The experiment consisted of four groups: control group, BLM group, and STE treatment groups (STE 50 and 100 mg/kg). ELISA and biochemical tests were conducted to determine the levels of TNF-α, IL-1β, IL-6, NO, hydroxyproline (HYP), SOD, GSH, and MDA. Histopathological changes and collagen deposition in lung tissues were observed by HE and Masson staining. Immunohistochemistry was performed to determine the levels of collagen I-, collagen III-, TGF-β1- and p-Smad2/3-positive cells. Western blot analysis was used to measure the expression of epithelial-mesenchymal transition (EMT) markers, including α-SMA, vimentin, E-cadherin, and ZO-1, as well as proteins related to the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, nuclear transcription factor-κB (NF-κB) pathway, and TGF-β1/Smad2/3 pathway in lung tissues. Results: STE significantly alleviated BLM-induced body weight loss and lung injury in mice, decreased HYP levels, and reduced the levels of collagen I- and collagen III-positive cells, thereby decreasing extracellular matrix (ECM) deposition. Moreover, STE markedly improved oxidative stress (MDA levels were decreased, while SOD and GSH activity were enhanced), the inflammatory response (the levels of TNF-α, IL-1β, IL-6, and NO were reduced), and EMT (the expression of α-SMA and vimentin was downregulated, and the expression of E-cadherin and ZO-1 was upregulated). Further mechanistic analysis revealed that STE could activate the Nrf2 pathway and inhibit the NF-κB and TGF-β1/Smad2/3 pathways. Conclusion: STE may alleviate oxidative stress by activating the Nrf2 pathway, suppress the inflammatory response by downregulating the NF-κB pathway, and inhibit EMT progression by blocking the TGF-β1/Smad2/3 pathway, thereby improving BLM-induced PF.

Risk of candidiasis associated with interleukin-17 inhibitors: Implications and management

The application of interleukin-17 (IL-17) inhibitors, including secukinumab, ixekizumab, brodalumab, and bimekizumab, are associated with elevated risk of candidiasis. These medications interfere with the IL-17 pathway, which is essential for maintaining mucosal barriers and coordinating the immune response against Candida species. The observational data and clinical trials demonstrate the increased incidence of candidiasis in individuals treated with IL-17 inhibitors. Brodalumab and bimekizumab pose a greater risk than secukinumab in eliciting candidiasis, whereas the data regarding ixekizumab are equivocal. Higher doses and prolonged treatment duration of IL-17 inhibitors increase the risk of candidiasis by compromising the immune response against Candida species. Prior to prescribing IL-17 inhibitors, healthcare professionals should comprehensively evaluate patients' medical histories and assess their risk factors. Patients should be educated on the signs and symptoms of candidiasis to facilitate early detection and intervention. Future research should focus on identifying the risk factors associated with candidiasis in patients receiving IL-17 inhibitors. Prospective studies and long-term surveillance are required to explore the impact of specific inhibitors on the incidence and severity of candidiasis and to evaluate the effectiveness of combination therapies, such as concurrent use of IL-17 inhibitors and prophylactic antifungal agents.

Constructing an extracellular matrix-related prognostic model for idiopathic pulmonary fibrosis based on machine learning

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease. Multiple research has revealed that the extracellular matrix (ECM) may be associated with the development and prognosis of IPF, however, the underlying mechanisms remain incompletely understood.

METHODS

We included GSE70866 dataset from the GEO database and established an ECM-related prognostic model utilizing LASSO, Random forest and Support vector machines algorithms. To compare immune cell infiltration levels between the high and low risk groups, we employed the ssGSEA algorithm. Enrichment analysis was conducted to explore pathway differences between the high-risk and low-risk groups. Finally, the model genes were validated using an external validation set consisting of IPF cases, as well as single-cell data analysis.

RESULTS

Based on machine learning algorithms, we constructed an ECM-related risk model. IPF patients in the high-risk group had a worse overall survival rate than those in the low-risk group. The model's AUC predictive values were 0.786, 0.767, and 0.768 for the 1-, 2-, and 3-year survival rates, respectively. The validation cohort validated these findings, demonstrating our model's effective prognostication. Chemokine-related pathways were enriched through enrichment analysis. Moreover, immune cell infiltration varied significantly between the two groups. Finally, the validation results indicate that the expression levels of all the model genes exhibited significant differential expression.

CONCLUSIONS

Based on CST6, PPBP, CSPG4, SEMA3B, LAMB2, SERPINB4 and CTF1, our study developed and validated an ECM-related risk model that accurately predicts the outcome of IPF patients.

Clinical Potential of Immunotherapies in Subarachnoid Hemorrhage Treatment: Mechanistic Dissection of Innate and Adaptive Immune Responses

Subarachnoid hemorrhage (SAH), classified as a medical emergency, is a devastating and severe subtype of stroke. SAH induces an immune response, which further triggers brain injury; however, the underlying mechanisms need to be further elucidated. The current research is predominantly focused on the production of specific subtypes of immune cells, especially innate immune cells, post-SAH onset. Increasing evidence suggests the critical role of immune responses in SAH pathophysiology; however, studies on the role and clinical significance of adaptive immunity post-SAH are limited. In this present study, we briefly review the mechanistic dissection of innate and adaptive immune responses post-SAH. Additionally, we summarized the experimental studies and clinical trials of immunotherapies for SAH treatment, which may form the basis for the development of improved therapeutic approaches for the clinical management of SAH in the future.

Genetic Association of Circulating Adipokines with Risk of Idiopathic Pulmonary Fibrosis: A Two-Sample Mendelian Randomization Study

PURPOSE

The causal relationships between circulating adipokines and idiopathic pulmonary fibrosis (IPF) are yet to be established. We performed a two-sample Mendelian randomization (MR) study to investigate the causal roles of adipokines on IPF risk.

METHODS

We analyzed the summary data from genome-wide association studies (GWAS), including adiponectin, leptin, resistin and monocyte chemoattractant protein-1 (MCP-1) and IPF. The inverse-variance weighted (IVW) method was considered as the major method and the MR-Egger, weighted median, simple mode and weighted mode were utilized as complementary methods. We also performed the sensitivity analyses, including heterogeneity test, horizontal pleiotropy test and leave-one-out analysis.

RESULTS

The selected number of single nucleotide polymorphisms (SNPs) was 13 for adiponectin, 6 for leptin,12 for resistin, and 6 for MCP-1, respectively. The results showed a causal effect of the circulating adiponectin levels on the risk of IPF (OR 0.645, 95% CI 0.457-0.911, P = 0.013). However, we did not observe significant associations of genetic changes in serum leptin (OR 1.018, 95% CI 0.442-2.346, P = 0.967), resistin (OR 1.002, 95% CI 0.712-1.408, P = 0.993), and MCP-1 (OR 1.358, 95% CI 0.891-2.068, P = 0.155) with risk of developing IPF. There was no evidence of heterogeneity or horizontal pleiotropy. The sensitivity analyses confirmed that our results were stable and reliable.

CONCLUSIONS

The increase in serum adiponectin was associated causally with a decreased risk of developing IPF. There is no evidence to support a causal association between leptin, resistin or MCP-1 with risk of IPF. Further studies are needed to confirm our findings.

Cellular mechanotransduction in health and diseases: from molecular mechanism to therapeutic targets

Cellular mechanotransduction, a critical regulator of numerous biological processes, is the conversion from mechanical signals to biochemical signals regarding cell activities and metabolism. Typical mechanical cues in organisms include hydrostatic pressure, fluid shear stress, tensile force, extracellular matrix stiffness or tissue elasticity, and extracellular fluid viscosity. Mechanotransduction has been expected to trigger multiple biological processes, such as embryonic development, tissue repair and regeneration. However, prolonged excessive mechanical stimulation can result in pathological processes, such as multi-organ fibrosis, tumorigenesis, and cancer immunotherapy resistance. Although the associations between mechanical cues and normal tissue homeostasis or diseases have been identified, the regulatory mechanisms among different mechanical cues are not yet comprehensively illustrated, and no effective therapies are currently available targeting mechanical cue-related signaling. This review systematically summarizes the characteristics and regulatory mechanisms of typical mechanical cues in normal conditions and diseases with the updated evidence. The key effectors responding to mechanical stimulations are listed, such as Piezo channels, integrins, Yes-associated protein (YAP) /transcriptional coactivator with PDZ-binding motif (TAZ), and transient receptor potential vanilloid 4 (TRPV4). We also reviewed the key signaling pathways, therapeutic targets and cutting-edge clinical applications of diseases related to mechanical cues.

Qilongtian ameliorate bleomycin-induced pulmonary fibrosis in mice via inhibiting IL-17 signal pathway

Pulmonary fibrosis (PF) is a special type of pulmonary parenchymal disease, with chronic, progressive, fibrosis, and high mortality. There is a lack of safe, effective, and affordable treatment methods. Qilongtian (QLT) is a traditional Chinese prescription that is composed of Panax notoginseng, Earthworm, and Rhodiola, and shows the remarkable clinical curative effect of PF. However, the mechanism of QLT remains to be clarified. Therefore, we studied the effectivity of QLT in treating Bleomycin (BLM) induced PF mice. 36 C57BL/6 J mice were randomized into the control group, the model group, the low-, medium- and high-dose QLT group, and Pirfenidone group. After establishing a model of pulmonary fibrosis in mice, the control and model groups were infused with a normal saline solution, and the delivery group was infused with QLT. Pulmonary function in the mice from each group was detected. Pulmonary tissue morphologies and collagen deposition were stained by HE and Masson. The content of hydroxyproline (HYP) was detected by alkaline hydrolysis and the mRNA and protein expression of related genes in pulmonary tissues were detected by using q-PCR, ELISA, and Western blot. Our studies have shown that QLT significantly reduced the inflammatory injury, hydroxy-proline content, and collagen deposition of pulmonary tissue in BLM-induced PF mice and down-regulated the cytokine related to inflammation and fibrosis and PF expression on the mRNA and protein level in PF mice. To identify the mechanism of QLT, the Transcriptome was measured and the IL-17 signal pathway was screened out for further research. Further studies indicated that QLT reduced the mRNAs and protein levels of interleukin 17 (IL-17), c-c motif chemokine ligand 12 (CCL12), c-x-c motif chemokine ligand 5 (CXCL5), fos-like antigen 1 (FOSL1), matrix metalloproteinase-9 (MMP9), and amphiregulin (AREG), which are inflammation and fibrosis-related genes in the IL-17 signal pathway. The results indicated that the potential mechanism for QLT in the prevention of PF progression was by inhibiting inflammation resulting in the IL-17 signal pathway. Our study provides the novel scientific basis of QLT and represents new therapeutics for PF in clinical.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

A comprehensive network map of IL-17A signaling pathway

Interleukin-17A (IL-17A) is one of the member of IL-17 family consisting of other five members (IL-17B to IL-17F). The Gamma delta (γδ) T cells and T helper 17 (Th17) cells are the major producers of IL-17A. Aberrant signaling by IL-17A has been implicated in the pathogenesis of several autoimmune diseases including idiopathic pulmonary fibrosis, acute lung injury, chronic airway diseases, and cancer. Activation of the IL-17A/IL-17 receptor A (IL-17RA) system regulates phosphoinositide 3-kinase/AKT serine/threonine kinase/mammalian target of rapamycin (PI3K/AKT/mTOR), mitogen-activated protein kinases (MAPKs) and activation of nuclear factor-κB (NF-κB) mediated signaling pathways. The IL-17RA activation orchestrates multiple downstream signaling cascades resulting in the release of pro-inflammatory cytokines such as interleukins (IL)-1β, IL-6, and IL-8, chemokines (C-X-C motif) and promotes neutrophil-mediated immune response. Considering the biomedical importance of IL-17A, we developed a pathway resource of signaling events mediated by IL-17A/IL-17RA in this study. The curation of literature data pertaining to the IL-17A system was performed manually by the NetPath criteria. Using data mined from the published literature, we describe an integrated pathway reaction map of IL-17A/IL-17RA consisting of 114 proteins and 68 reactions. That includes detailed information on IL-17A/IL-17RA mediated signaling events of 9 activation/inhibition events, 17 catalysis events, 3 molecular association events, 68 gene regulation events, 109 protein expression events, and 6 protein translocation events. The IL-17A signaling pathway map data is made freely accessible through the WikiPathways Database ( https://www.wikipathways.org/index.php/Pathway : WP5242).

Adipose tissue-derived mesenchymal stem cells attenuate lung inflammation and fibrosis in the bleomycin-induced pulmonary fibrosis rat model via caveolin-1/NF-kB signaling axis

Stem cells have emerged as promising therapeutic options for several human diseases, including pulmonary fibrosis (PF). In this study, we investigated the therapeutic effects of adipose tissue-derived mesenchymal stem cells (ADMSCs) in the bleomycin-induced PF model rats and the underlying mechanisms. The PF model rats were generated by intratracheal injections of 5 mg/kg bleomycin sulfate. The ADMSC group rats were generated by injecting 2×10(6) ADMSCs via the tail vein at 0, 12, and 24 h after bleomycin injection. The control, PF, and ADMSC group rats were sacrificed on day 21 after bleomycin injections and the changes in lung histology and the levels of pro-inflammatory cytokines, collagen I, and caveolin-1 (Cav-1), and the activity of the NF-kappaB signaling pathway in the lung tissues was assessed by hematoxylin-eosin staining, ELISA, and western blotting assays. The lung tissues of the PF model rats showed significant infiltration of neutrophils, tissue destruction, and collagen deposition, but these effects were abrogated by the ADMSCs. The levels of pro-inflammatory cytokines such as IL-6, IL-1beta, and TGF-beta1 were elevated in the lung tissues and the bronchoalveolar lavage fluid (BALF) of the bleomycin-induced PF model rats, but these effects were reversed by the ADMSCs. The lung tissues of the PF model rats showed significant downregulation of Cav-1 and significantly higher activation of the pro-inflammatory NF-kappaB pathway. However, administration of the ADMSCs restored the expression levels of Cav-1 and suppressed the NF-kappaB signaling pathway in the lungs of the bleomycin-induced PF model rats. In conclusion, this study demonstrated that the ADMSCs protected against bleomycin-induced PF in the rat model by modulating the Cav-1/NF-kappaB axis.

Construction of prediction model of inflammation related genes in idiopathic pulmonary fibrosis and its correlation with immune microenvironment

BACKGROUND

The role of inflammation in the formation of idiopathic pulmonary fibrosis (IPF) has gained a lot of attention recently. However, the involvement of genes related to inflammation and immune exchange environment status in the prognosis of IPF remains to be further clarified. The objective of this research is to establish a new model for the prediction of the overall survival (OS) rate of inflammation-related IPF.

METHODS

Gene Expression Omnibus (GEO) was employed to obtain the three expression microarrays of IPF, including two from alveolar lavage fluid cells and one from peripheral blood mononuclear cells. To construct the risk assessment model of inflammation-linked genes, least absolute shrinkage and selection operator (lasso), univariate cox and multivariate stepwise regression, and random forest method were used. The proportion of immune cell infiltration was evaluated by single sample Gene Set Enrichment Analysis (ssGSEA) algorithm.

RESULTS

The value of genes linked with inflammation in the prognosis of IPF was analyzed, and a four-genes risk model was constructed, including tpbg, Myc, ffar2, and CCL2. It was highlighted by Kaplan Meier (K-M) survival analysis that patients with high-risk scores had worse overall survival time in all training and validation sets, and univariate and multivariate analysis highlighted that it has the potential to act as an independent risk indicator for poor prognosis. ROC analysis showed that the prediction efficiency of 1-, 3-, and 5-year OS time in the training set reached 0.784, 0.835, and 0.921, respectively. Immune infiltration analysis showed that Myeloid-Derived Suppressor Cells (MDSC), macrophages, regulatory T cells, cd4+ t cells, neutrophils, and dendritic cells were more infiltrated in the high-risk group than in the low-risk group.

CONCLUSION

Inflammation-related genes can be well used to evaluate the IPF prognosis and impart a new idea for the treatment and follow-up management of IPF patients.