T Cells in Fibrosis and Fibrotic Diseases

Identification of common and specific fibrosis-related genes in three common chronic kidney diseases

BACKGROUND

Kidney fibrosis is the common final pathway of virtually all advanced forms of chronic kidney disease (CKD) including diabetic nephropathy (DN), IgA nephropathy (IgAN) and membranous nephropathy (MN), with complex mechanism. Comparative gene expression analysis among these types of CKD may shed light on its pathogenesis. Therefore, we conducted this study aiming at exploring the common and specific fibrosis-related genes involved in different types of CKD.

METHODS

Kidney biopsy specimens from patients with different types of CKD and normal control subjects were analyzed using the NanoString nCounter® Human Fibrosis V2 Panel. Genes differentially expressed in all fibrotic DN, IgAN and MN tissues compared to the normal controls were regarded as the common fibrosis-related genes in CKD, whereas genes exclusively differentially expressed in fibrotic DN, IgAN or MN samples were considered to be the specific genes related to fibrosis in DN, IgAN and MN respectively. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of the selected genes.

RESULTS

Protein tyrosine phosphatase receptor type C (PTPRC), intercellular cell adhesion molecule-1 (ICAM1), vascular cell adhesion molecule-1 (VCAM1), interleukin 10 receptor alpha (IL10RA) and CC chemokine receptor 2 (CCR2) were identified as the potential common genes for kidney fibrosis in different types of CKD, while peroxisome proliferator-activated receptor alpha (PPARA), lactate oxidase (LOX), secreted phosphoprotein 1 (SPP1) were identified as the specific fibrosis-associated genes for DN, IgAN and MN respectively. qRT-PCR demonstrated that the expression levels of these selected genes were consistent with the NanoString analysis.

CONCLUSIONS

There were both commonalities and differences in the mechanisms of fibrosis in different types of CKD, the commonalities might be used as the common therapeutic targets for kidney fibrosis in CKD, while the differences might be used as the diagnostic markers for DN, IgAN and MN respectively. Inflammation was highly relevant to the pathogenesis of fibrosis. This study provides further insight into the pathophysiology and treatment of fibrotic kidney disease.

Advances in the understanding of the role and mechanism of action of PFKFB3‑mediated glycolysis in liver fibrosis (Review)

Liver fibrosis is a pathophysiologic manifestation of chronic liver disease and a precursor to cirrhosis and hepatocellular carcinoma. Glycolysis provides intermediate metabolites as well as energy support for cell proliferation and phenotypic transformation in liver fibers. 6‑Phosphofructo‑2‑kinase/fructose‑2,6‑bisphosphatase 3 (PFKFB3) is a key activator of glycolysis and plays an important role in the process of glycolysis. The role of PFKFB3‑mediated glycolysis in myocardial fibrosis, renal fibrosis and pulmonary fibrosis has been demonstrated, and the role of PFKFB3 in the activation of hepatic stellate cells by aerobic glycolysis has been proven by relevant experiments. The present study reviews the research progress on the role and mechanism of action of PFKFB3‑mediated glycolysis in the progression of hepatic fibrosis to discuss the role of PFKFB3‑mediated glycolysis in hepatic fibrosis and to provide new ideas for research on PFKFB3 as a target for the treatment of hepatic fibrosis.

Ficus hirta Vahl. ameliorates liver fibrosis by triggering hepatic stellate cell ferroptosis through GSH/GPX4 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus hirta Vahl., a traditional Chinese medicine commonly used in the Lingnan region, has been extensively used for liver disease treatment in China. Its notable antioxidant and anti-inflammatory properties have been reported in previous studies. However, its potential effect and underlying mechanism on liver fibrosis remains unclear.

AIM OF STUDY

This study was aimed to investigate the effect and its underlying mechanism of Ficus hirta Vahl on liver fibrosis in vitro and in vivo.

MATERIALS AND METHODS

The main components of Ficus hirta Vahl in blood were investigated by using UPLC-Q/TOF-MS/MS. Two animal models of liver fibrosis, the CCl4 and MCD induced mice, were used to assess the efficacy of Ficus hirta Vahl on liver fibrosis. Metabolomics was used to detect the level of metabolites in the serum of liver fibrosis mice after Ficus hirta Vahl treatment. Furthermore, the mechanism was validated in vitro using the human liver stellate cell line LX-2. The binding affinities of the active ingredients of Ficus hirta Vahl to the main targets of liver fibrosis were also determined. Finally, we identified the key active ingredients responsible for the treatment of liver fibrosis in vivo.

RESULTS

Fibrosis and inflammatory markers were significant down-regulation in both CCl4 and MCD induced liver fibrosis mice after Ficus hirta Vahl administration in a dose-dependent manner. We found that Ficus hirta Vahl may primarily exert its effect on liver fibrosis through the glutathione metabolic pathway. Importantly, the glutathione metabolic pathway is closely associated with ferroptosis, and our subsequent in vitro experiments provided evidence supporting this association. Ficus hirta Vahl was found to modulate the GSH/GPX4 pathway, ultimately leading to the amelioration of liver fibrosis. Moreover, using serum pharmacochemistry and molecular docking, we successfully identified apigenin as a probable efficacious monomer for the management of liver fibrosis and subsequently validated its efficacy in mice with CCl4-induced hepatic fibrosis.

CONCLUSION

Ficus hirta Vahl triggered the ferroptosis of hepatic stellate cell by regulating the GSH/GPX4 pathway, thereby alleviating liver fibrosis in mice. Moreover, apigenin is a key compound in Ficus hirta Vahl responsible for the effective treatment of liver fibrosis.

Causal effect of immune cells on idiopathic pulmonary fibrosis: A mendelian randomization study

BACKGROUND

A key component of idiopathic pulmonary fibrosis (IPF) is the involvement of immune cells. However, the causal interaction between different immune cell signatures and IPF remain inconclusive.

OBJECTIVES

Based on publicly accessible data, our study utilized the Mendelian randomization (MR) approach to determine the causative relevance of complex immune cell phenotypes in IPF.

METHODS

We deployed a two-sample Mendelian randomization approach to evaluate the causal interaction between immune cell markers and IPF. All data regarding 731 immune signatures and IPF were acquired from two genome-wide association studies (GWAS) that are accessible to the public. The original study adopted the inverse variance weighted (IVW) method, followed by sensitivity analyses aimed at eliminating heterogeneity and pleiotropy. Additionally, Multivariate Mendelian randomization (MVMR) was utilized to identify the independent risk factors in our study.

RESULTS

The summary dataset for IPF was accessed from the Finnish Genetic Consortium R9, comprising 2018 patients and 373,064 controls. And the dataset for immune signatures was conducted in 3,757 Sardinian individuals. By conducting IVW and extensive sensitivity analyses, univariate Mendelian randomization (UVMR) identified one immunophenotype that remained causally associated with IPF after false discovery rate (FDR) correction: CD39 on CD39+ CD8+T cells (odd ratio [OR] = 0.850, 95 % confidence interval [CI] = 0.787-0.918, P = 3.68 × 10-5). The causal association with IPF was further validated using MVMR.

CONCLUSIONS

Based on rigorous MR analysis methods and FDR correction, our study demonstrated that CD39 on CD39+ CD8+T cells showed a protective effect against IPF, providing effective insights for preventing and diagnosing pulmonary fibrosis.

S100A2 activation promotes interstitial fibrosis in kidneys by FoxO1-mediated epithelial-mesenchymal transition

BACKGROUND

Renal interstitial fibrosis (RIF) is a common feature of chronic kidney diseases (CKD), with epithelial-mesenchymal transition (EMT) being one of its important mechanisms. S100A2 is a protein associated with cell proliferation and differentiation, but its specific functions and molecular mechanisms in RIF remain to be determined.

METHODS

S100A2 levels were evaluated in three mouse models, including unilateral ureteral obstruction (UUO), ischemia-reperfusion injury (IRI), and aristolochic acid nephropathy (AAN), as well as in TGF-β1- treated HK-2 cells and in kidney tissue samples. Furthermore, the role of S100A2 and its interaction with FoxO1 was investigated using RT-qPCR, immunoblotting, immunofluorescence staining, co-immunoprecipitation (Co-IP), transcriptome sequencing, and gain- or loss-of-function approaches in vitro.

RESULTS

Elevated expression levels of S100A2 were observed in three mouse models and TGF-β1-treated HK2 cells, as well as in kidney tissue samples. Following siRNA silencing of S100A2, exposure to TGF-β1 in cultured HK-2 cells suppressed EMT process and extracellular matrix (ECM) accumulation. Conversely, Overexpression of S100A2 induced EMT and ECM deposition. Notably, we identified that S100A2-mediated EMT depends on FoxO1. Immunofluorescence staining indicated that S100A2 and FoxO1 colocalized in the nucleus and cytoplasm, and their interaction was verified in Co-IP assay. S100A2 knockdown decreased TGF-β1-induced phosphorylation of FoxO1 and increased its protein expression, whereas S100A2 overexpression hampered FoxO1 activation. Furthermore, pharmacological blockade of FoxO1 rescued the induction of TGF-β1 on EMT and ECM deposition in S100A2 siRNA-treated cells.

CONCLUSION

S100A2 activation exacerbates interstitial fibrosis in kidneys by facilitating FoxO1-mediated EMT.

Jag1 insufficiency alters liver fibrosis via T cell and hepatocyte differentiation defects

Fibrosis contributes to tissue repair, but excessive fibrosis disrupts organ function. Alagille syndrome (ALGS, caused by mutations in JAGGED1) results in liver disease and characteristic fibrosis. Here, we show that Jag1Ndr/Ndr mice, a model for ALGS, recapitulate ALGS-like fibrosis. Single-cell RNA-seq and multi-color flow cytometry of the liver revealed immature hepatocytes and paradoxically low intrahepatic T cell infiltration despite cholestasis in Jag1Ndr/Ndr mice. Thymic and splenic regulatory T cells (Tregs) were enriched and Jag1Ndr/Ndr lymphocyte immune and fibrotic capacity was tested with adoptive transfer into Rag1-/- mice, challenged with dextran sulfate sodium (DSS) or bile duct ligation (BDL). Transplanted Jag1Ndr/Ndr lymphocytes were less inflammatory with fewer activated T cells than Jag1+/+ lymphocytes in response to DSS. Cholestasis induced by BDL in Rag1-/- mice with Jag1Ndr/Ndr lymphocytes resulted in periportal Treg accumulation and three-fold less periportal fibrosis than in Rag1-/- mice with Jag1+/+ lymphocytes. Finally, the Jag1Ndr/Ndr hepatocyte expression profile and Treg overrepresentation were corroborated in patients' liver samples. Jag1-dependent hepatic and immune defects thus interact to determine the fibrotic process in ALGS.

WNT2B high‑expressed fibroblasts induce the fibrosis of IBD by promoting NK cells secreting IL-33

Fibrosis is an important pathological change in inflammatory bowel disease (IBD), but the mechanism has yet to be elucidated. WNT2B high‑expressed fibroblasts are enriched in IBD intestinal tissues, although the precise function of this group of fibroblasts remains unclear. This study investigated whether WNT2B high‑expressed fibroblasts aggravated intestinal tissue damage and fibrosis. Our study provides evidence that WNT2B high‑expressed fibroblasts and NK cells were enriched in colitis tissue of patients with IBD. WNT2B high‑expressed fibroblasts secreted wnt2b, which bound to FZD4 on NK cells and activated the NF-κB and STAT3 pathways to enhance IL-33 expression. TCF4, a downstream component of the WNT/β-catenin pathway, bound to p65 and promoted binding to IL-33 promoter. Furthermore, Salinomycin, an inhibitor of the WNT/β-catenin pathway, inhibited IL-33 secretion in colitis, thereby reducing intestinal inflammation.Knocking down WNT2B reduces NK cell infiltration and IL-33 secretion in colitis, and reduce intestinal inflammation and fibrosis. In conclusion, WNT2B high‑expressed fibroblasts activate NK cells by secreting wnt2b, which activates the WNT/β-catenin and NF-κB pathways to promote IL-33 expression and secretion, potentially culminating in the induction of colonic fibrosis in IBD. KEY MESSAGES: WNT2B high-expressed fibroblasts and NK cells are enriched in colitis tissue, promoting NK cells secreting IL-33. Wnt2b activates NF-κB and STAT3 pathways promotes IL-33 expression by activating p65 and not STAT3. syndrome TCF4 binds to p65 and upregulates the NF- κB pathway. Salinomycin reduces NK cell infiltration and IL-33 secretion in colitis. Knocking down WNT2B mitigates inflammation and fibrosis in chronic colitis.

The potential of flavonoids in hepatic fibrosis: A comprehensive review

BACKGROUND

Hepatic fibrosis is a pathophysiological process of extracellular matrix abnormal deposition induced by multiple pathogenic factors. Currently, there is still a lack of effective and non-toxic drugs for treating fibrosis in clinic. Flavonoids are polyphenolic compounds synthesized in plants and modern pharmacological studies confirmed flavonoids exhibit potent hepatoprotective effect.

PURPOSE

Summarize literature to elaborate the mechanism of HF and evaluate the potential of flavonoids in HF, aiming to provide a new perspective for future research.

METHODS

The literatures about hepatic fibrosis and flavonoids are collected via a series of scientific search engines including Google Scholar, Elsevier, PubMed, CNKI, WanFang, SciFinder and Web of Science database. The key words are "flavonoids", "hepatic fibrosis", "pharmacokinetic", "toxicity", "pathogenesis" "traditional Chinese medicine" and "mechanism" as well as combination application.

RESULTS

Phytochemical and pharmacological studies revealed that about 86 natural flavonoids extracted from Chinese herbal medicines possess significantly anti-fibrosis effect and the mechanisms maybe through anti-inflammatory, antioxidant, inhibiting hepatic stellate cells activation and clearing activated hepatic stellate cells.

CONCLUSIONS

This review summarizes the flavonoids which are effective in HF and the mechanisms in vivo and in vitro. However, fewer studies are focused on the pharmacokinetics of flavonoids in HF model and most studies are limited to preclinical studies, therefore there is no reliable data from clinical trials for the development of new drugs. Further in-depth research related it can be conducted to improve the bioavailability of flavonoids and serve the development of new drugs.

Targeting the chromatin binding of exportin-1 disrupts NFAT and T cell activation

Exportin-1 (XPO1/CRM1) plays a central role in the nuclear-to-cytoplasmic transport of hundreds of proteins and contributes to other cellular processes, such as centrosome duplication. Small molecules targeting XPO1 induce cytotoxicity, and selinexor was approved by the Food and Drug Administration in 2019 as a cancer chemotherapy for relapsed multiple myeloma. Here, we describe a cell-type-dependent chromatin-binding function for XPO1 that is essential for the chromatin occupancy of NFAT transcription factors and thus the appropriate activation of T cells. Additionally, we establish a class of XPO1-targeting small molecules capable of disrupting the chromatin binding of XPO1 without perturbing nuclear export or inducing cytotoxicity. This work defines a broad transcription regulatory role for XPO1 that is essential for T cell activation as well as a new class of XPO1 modulators to enable therapeutic targeting of XPO1 beyond oncology including in T cell-driven autoimmune disorders.

Identification of macrophage driver genes in fibrosis caused by different heart diseases based on omics integration

BACKGROUND

Myocardial fibrosis, a hallmark of heart disease, is closely associated with macrophages, yet the genetic pathophysiology remains incompletely understood. In this study, we utilized integrated single-cell transcriptomics and bulk RNA-seq analysis to investigate the relationship between macrophages and myocardial fibrosis across omics integration.

METHODS

We examined and curated existing single-cell data from dilated cardiomyopathy (DCM), ischemic cardiomyopathy (ICM), myocardial infarction (MI), and heart failure (HF), and analyzed the integrated data using cell communication, transcription factor identification, high dimensional weighted gene co-expression network analysis (hdWGCNA), and functional enrichment to elucidate the drivers of macrophage polarization and the macrophage-to-myofibroblast transition (MMT). Additionally, we assessed the accuracy of single-cell data from the perspective of driving factors, cell typing, anti-fibrosis performance of left ventricular assist device (LVAD). Candidate drugs were screened using L1000FWD.

RESULTS

All four heart diseases exhibit myocardial fibrosis, with only MI showing an increase in macrophage proportions. Macrophages participate in myocardial fibrosis through various fibrogenic molecules, especially evident in DCM and MI. Abnormal RNA metabolism and dysregulated transcription are significant drivers of macrophage-mediated fibrosis. Furthermore, profibrotic macrophages exhibit M1 polarization and increased MMT. In HF patients, those responding to LVAD therapy showed a significant decrease in driver gene expression, M1 polarization, and MMT. Drug repurposing identified cinobufagin as a potential therapeutic agent.

CONCLUSION

Using integrated single-cell transcriptomics, we identified the drivers of macrophage-mediated myocardial fibrosis in four heart diseases and confirmed the therapeutic effect of LVAD on improving HF with single-cell accuracy, providing novel insights into the diagnosis and treatment of myocardial fibrosis.

Human mesenchymal stromal cells ameliorate cisplatin-induced acute and chronic kidney injury via TSG-6

Cisplatin is widely used in tumor chemotherapy, but nephrotoxicity is an unavoidable side effect of cisplatin. Several studies have demonstrated that mesenchymal stromal cells (MSCs) ameliorate cisplatin-induced kidney injury, but the underlying mechanisms are unknown. In this study, the cisplatin-induced kidney injury mouse model was established by subjecting a single intraperitoneal injection with cisplatin. One hour before cisplatin injection, the mice received human bone marrow MSCs (hBM-MSCs) with or without siRNA-transfection, recombinant human tumor necrosis factor-α-stimulated gene/protein 6 (rhTSG-6), or PBS through the tail vein. In addition, cisplatin-stimulated HK-2 cells were treated with hBM-MSCs or rhTSG-6. Human BM-MSCs treatment remarkably ameliorated cisplatin-induced acute and chronic kidney injury, as evidenced by significant reductions in serum creatinine (Scr), blood urea nitrogen, tubular injury, collagen deposition, α-smooth muscle actin accumulation, as well as inflammatory responses, and by remarkable increased anti-inflammatory factor expression and Treg cells infiltration in renal tissues. Furthermore, we found that only a few hBM-MSCs engrafted into damaged kidney and that the level of human TSG-6 in the serum of mice increased significantly following hBM-MSCs administration. Moreover, hBM-MSCs significantly increased the viability of damaged HK-2 cells and decreased the levels of inflammatory cytokines in the culture supernatant. However, the knockdown of the TSG-6 gene in hBM-MSCs significantly attenuated their beneficial effects in vivo and in vitro. On the contrary, treated with rhTSG-6 achieved similar beneficial effects of hBM-MSCs. Our results indicate that systemic administration of hBM-MSCs alleviates cisplatin-induced acute and chronic kidney injury in part by paracrine TSG-6 secretion.

Human placental mesenchymal stromal cells promote the formation of CD8+CD122+PD-1+Tregs via CD73/Foxo1 to alleviate liver injury in graft-versus-host disease mice

BACKGROUND

Human placental mesenchymal stromal cells (hPMSCs) are known to limit graft-versus-host disease (GVHD). CD8+CD122+PD-1+Tregs have been shown to improve the survival of GVHD mice. However, the regulatory roles of hPMSCs in this subgroup remain unclear. Here, the regulatory mechanism of hPMSCs in reducing liver fibrosis in GVHD mice by promoting CD8+CD122+PD-1+Tregs formation and controlling the balance of IL-6 and IL-10 were explored.

METHODS

A GVHD mouse model was constructed using C57BL/6J and BALB/c mice and treated with hPMSCs. LX-2 cells were explored to study the effects of IL-6 and IL-10 on the activation of hepatic stellate cells (HSCs). The percentage of CD8+CD122+PD-1+Tregs and IL-10 secretion were determined using FCM. Changes in hepatic tissue were analysed by HE, Masson, multiple immunohistochemical staining and ELISA, and the effects of IL-6 and IL-10 on LX-2 cells were detected using western blotting.

RESULTS

hPMSCs enhanced CD8+CD122+PD-1+Treg formation via the CD73/Foxo1 and promoted IL-10, p53, and MMP-8 levels, but inhibited IL-6, HLF, α-SMA, Col1α1, and Fn levels in the liver of GVHD mice through CD73. Positive and negative correlations of IL-6 and IL-10 between HLF were found in liver tissue, respectively. IL-6 upregulated HLF, α-SMA, and Col1α1 expression via JAK2/STAT3 pathway, whereas IL-10 upregulated p53 and inhibited α-SMA and Col1α1 expression in LX-2 cells by activating STAT3.

CONCLUSIONS

hPMSCs promoted CD8+CD122+PD-1+Treg formation and IL-10 secretion but inhibited HSCs activation and α-SMA and Col1α1 expression by CD73, thus controlling the balance of IL-6 and IL-10, and alleviating liver injury in GVHD mice.

Peripheral Th17/Treg imbalance in Chinese patients with untreated antisynthetase syndrome associated interstitial lung disease

Interstitial lung disease (ILD) is a common and fatal manifestation of antisynthetase syndrome (ASS). The aim of this study was to provide new insight into investigate peripheral blood lymphocytes, CD4+ T cells, cytokine levels and their relation to the clinical profile of untreated patients with ASS-ILD. The retrospective study population included thirty patients diagnosed with ASS-ILD and 30 healthy controls (HCs). Baseline clinical and laboratory data were collected for all subjects, including peripheral blood lymphocyte, CD4+ T cell subsets measured by flow cytometry, and serum cytokine levels measured by multiple microsphere flow immunofluorescence. Their correlations with clinical and laboratory findings were analyzed by Pearson's or Spearman's correlation analysis. In addition, the Benjamini-Hochberg method was used for multiple correction to adjust the p-values. Patients with ASS-ILD had lower CD8+ T cells, higher proportion of Th17 cells and Th17/Treg ratio than HCs. Serum cytokine levels (IL-1β, IL-6, IL-12, IL-17, IL-8, IL-2, IL-4, IL-10, TNF-α and IFN-γ) were higher in patients with ASS-ILD than HCs. Moreover, Th17/Treg ratio was negatively correlated with diffusing capacity of carbon monoxide (DLCO)%. Our study demonstrated abnormalities of immune disturbances in patients with ASS-ILD, characterized by decreased CD8+ T cells and an increased Th17/Treg ratio, due to an increase in the Th17 cells. These abnormalities may be the immunological mechanism underlying the development of ILD in ASS.

Spatial transcriptomics defines injury specific microenvironments and cellular interactions in kidney regeneration and disease

Kidney injury disrupts the intricate renal architecture and triggers limited regeneration, together with injury-invoked inflammation and fibrosis. Deciphering the molecular pathways and cellular interactions driving these processes is challenging due to the complex tissue structure. Here, we apply single cell spatial transcriptomics to examine ischemia-reperfusion injury in the mouse kidney. Spatial transcriptomics reveals injury-specific and spatially-dependent gene expression patterns in distinct cellular microenvironments within the kidney and predicts Clcf1-Crfl1 in a molecular interplay between persistently injured proximal tubule cells and their neighboring fibroblasts. Immune cell types play a critical role in organ repair. Spatial analysis identifies cellular microenvironments resembling early tertiary lymphoid structures and associated molecular pathways. Collectively, this study supports a focus on molecular interactions in cellular microenvironments to enhance understanding of injury, repair and disease.

Changes in T-cell subsets occur in interstitial lung disease and may contribute to pathology via complicated immune cascade

The study aimed to investigate the expression profiles of transcription factors, cytokines, and co-stimulatory molecules in helper T (Th)-cell subsets within bronchoalveolar lavage (BAL) samples of patients with interstitial lung diseases (ILDs). Twenty ILDs patients were included in the study, comprising those with idiopathic pulmonary fibrosis (IPF) (n:8), autoimmune-related ILDs (auto-ILD) (n:4), and orphan diseases (O-ILD) (n:8), alongside five control subjects. Flow cytometry was employed to evaluate the Th to cytotoxic T cell (CTL) ratio in BAL fluid, while cytopathological examination assessed macrophages, lymphocytes, and neutrophils. Quantitative real-time polymerase chain reaction was utilized to investigate the expressions in Th1, Th2, Th17, and regulatory T (Treg) cells. Results revealed elevated Th cell to CTL ratios across all patient groups compared to controls. Furthermore, upregulation of Th1, Th2, Th17, and T-cell factors was observed in all patient groups compared to controls. Interestingly, upregulation of CD28 and downregulation of CTLA-4 and PD-1 gene expression were consistent across all ILDs groups, highlighting potential immune dysregulation. This study provides a comprehensive exploration of molecular immunological mechanisms in ILDs patients, underscoring the dominance of Th2 and Th17 responses and revealing novel findings regarding the dysregulation of CD28, CTLA-4, and PD-1 expressions in ILDs for the first time.

Integrative Transcriptomic Analysis of Peripheral Blood Monocytes in Systemic Sclerosis and Shared Pathogenic Pathways in Autoimmune Diseases

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disease (AD), that receives less attention compared to rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and primary Sjögren's syndrome (pSS). This study aims to analyze transcriptional profiles and immune cell composition in peripheral blood mononuclear cells (PBMC) from SSc patients compared to other ADs.

METHODS

RNA-seq data from 119 untreated patients (eight with SSc, 42 with RA, 41 with pSS, 28 with SLE) and 20 healthy controls were analyzed. Bioinformatics tools were employed to identify differentially expressed genes (DEGs), biological functions and immune cell profiles unique to SSc and shared with other ADs.

RESULTS

1,148 DEGs were found in SSc, with upregulated genes associated with megakaryocyte processes and downregulated genes associated with neutrophil function and immune response. DEGs, including ALDH1A1 and MEGF9, were associated with neutropenia. Upregulated transcription factors (TFs) were linked to embryonic hematopoiesis and downregulated TFs were involved in leukocyte differentiation and immune regulation. Comparative analysis with other ADs revealed common pathogenic pathways, emphasizing megakaryocyte proliferation. Neutrophils count was significantly decreased in ADs (p < 0.001) compared to healthy controls. Comparative analysis highlighted common pathways, particularly in megakaryocyte proliferation, and unique genes (MEGF9, MMP8, and KRT family members) in SSc, suggesting roles in neutrophil function, skin integrity, and fibrosis.

CONCLUSIONS

This study identifies dysregulated gene expression (KRT and MMP8) associated with neutrophil function and increased megakaryocytes in SSc, highlighting common patterns across autoimmune diseases. These findings offer new insights into the potential pathogenesis of SSc, and help to explore new targets for the treatment.

Fibrosis-on-Chip: A Guide to Recapitulate the Essential Features of Fibrotic Disease

Fibrosis, which is primarily marked by excessive extracellular matrix (ECM) deposition, is a pathophysiological process associated with many disorders, which ultimately leads to organ dysfunction and poor patient outcomes. Despite the high prevalence of fibrosis, currently there exist few therapeutic options, and importantly, there is a paucity of in vitro models to accurately study fibrosis. This review discusses the multifaceted nature of fibrosis from the viewpoint of developing organ-on-chip (OoC) disease models, focusing on five key features: the ECM component, inflammation, mechanical cues, hypoxia, and vascularization. The potential of OoC technology is explored for better modeling these features in the context of studying fibrotic diseases and the interplay between various key features is emphasized. This paper reviews how organ-specific fibrotic diseases are modeled in OoC platforms, which elements are included in these existing models, and the avenues for novel research directions are highlighted. Finally, this review concludes with a perspective on how to address the current gap with respect to the inclusion of multiple features to yield more sophisticated and relevant models of fibrotic diseases in an OoC format.

Involvement of PD-1+CD4+ T cells in the development of traumatic tracheal stenosis by regulating the IL-17/STAT3 pathway

Studies have highlighted an upregulation of PD-1 expression in CD4+ T cells, which accelerates lung fibrosis by activating the IL-17/STAT3 pathway, leading to IL-17A and TGF-β1 secretion. However, the relation with traumatic tracheal stenosis (TS) remains unexplored. Our analysis found significant increases in PD-1+CD4+ T cells, IL-17A, and TGF-β1 in the TS patients (n = 10). The cellular model used CD4+ T cells co-cultured with bronchial fibroblasts while the animal model used a nylon brush to scrape the damaged tracheal mucosa. Interventions with PD-1 and STAT3 inhibitors both in vitro (n = 5) and in vivo (n = 6) showed decreased expression of TGF-β1 and IL-17A in CD4+ T cells, decreased collagen I synthesis in vitro, and reduced tractal fibrosis in vivo. Furthermore, PD-1's modulation of the STAT3 was evident. This research unveils PD-1+CD4+ T cells' role in TS, thus suggesting a novel immunotherapeutic strategy to counteract tracheal fibrosis.

Salvianolic acid B in fibrosis treatment: a comprehensive review

Fibrosis is a public health issue of great concern characterized by the excessive deposition of extracellular matrix, leading to the destruction of parenchymal tissue and organ dysfunction that places a heavy burden on the global healthcare system due to its high incidence, disability, and mortality. Salvianolic acid B (SalB) has positively affected various human diseases, including fibrosis. In this review, we concentrate on the anti-fibrotic effects of SalB from a molecular perspective while providing information on the safety, adverse effects, and drug interactions of SalB. Additionally, we discuss the innovative SalB formulations, which give some references for further investigation and therapeutic use of SalB's anti-fibrotic qualities. Even with the encouraging preclinical data, additional research is required before relevant clinical trials can be conducted. Therefore, we conclude with recommendations for future studies. It is hoped that this review will provide comprehensive new perspectives on future research and product development related to SalB treatment of fibrosis and promote the efficient development of this field.

Roles and therapeutic targeting of dendritic cells in liver fibrosis

Liver fibrosis is a common pathological condition marked by excessive accumulation of extracellular matrix proteins, resulting in irreversible cirrhosis and cancer. Dendritic cells (DCs) act as the crucial component of hepatic immunity and are believed to affect fibrosis by regulating the proliferation and differentiation of hepatic stellate cells (HSCs), a key mediator of fibrogenesis, and by interplaying with immune cells in the liver. This review concisely describes the process of fibrogenesis, and the phenotypic and functional characteristics of DCs in the liver. Besides, it focuses on the interaction between DCs and HSCs, T cells, and natural killer (NK) cells, as well as the dual roles of DCs in liver fibrosis, for the sake of exploring the potential of targeting DCs as a therapeutic strategy for the disease.

Fibrostricturing Crohn's Disease Is Marked by an Increase in Active Eosinophils in the Deeper Layers

INTRODUCTION

Approximately 50% of patients with Crohn's disease (CD) develop intestinal strictures necessitating surgery. The immune cell distribution in these strictures remains uncharacterized. We aimed to identify the immune cells in intestinal strictures of patients with CD.

METHODS

During ileocolonic resections, transmural sections of terminal ileum were sampled from 25 patients with CD and 10 non-inflammatory bowel disease controls. Macroscopically unaffected, fibrostenotic, and inflamed ileum was collected and analyzed for immune cell distribution (flow cytometry) and protein expression. Collagen deposition was assessed through a Masson Trichrome staining. Eosinophil and fibroblast colocalization was assessed through immunohistochemistry.

RESULTS

The Masson Trichrome staining confirmed augmented collagen deposition in both the fibrotic and the inflamed regions, though with a significant increased collagen deposition in the fibrotic compared with inflamed tissue. Distinct Th1, Th2, regulatory T cells, dendritic cells, and monocytes were identified in fibrotic and inflamed CD ileum compared with unaffected ileum of patients with CD as non-inflammatory bowel disease controls. Only minor differences were observed between fibrotic and inflamed tissue, with more active eosinophils in fibrotic deeper layers and increased eosinophil cationic protein expression in inflamed deeper layers. Last, no differences in eosinophil and fibroblast colocalization were observed between the different regions.

DISCUSSION

This study characterized immune cell distribution and protein expression in fibrotic and inflamed ileal tissue of patients with CD. Immunologic, proteomic, and histological data suggest inflammation and fibrosis are intertwined, with a large overlap between both tissue types. However strikingly, we did identify an increased presence of active eosinophils only in the fibrotic deeper layers, suggesting their potential role in fibrosis development.

Possible Role of Gut Microbiota Alterations in Myocardial Fibrosis and Burden of Heart Failure in Hypertensive Heart Disease

Epidemiological studies have revealed that hypertensive heart disease is a major risk factor for heart failure, and its heart failure burden is growing rapidly. The need to act in the face of this threat requires first an understanding of the multifactorial origin of hypertensive heart disease and second an exploration of new mechanistic pathways involved in myocardial alterations critically involved in cardiac dysfunction and failure (eg, myocardial interstitial fibrosis). Increasing evidence shows that alterations of gut microbiota composition and function (ie, dysbiosis) leading to changes in microbiota-derived metabolites and impairment of the gut barrier and immune functions may be involved in blood pressure elevation and hypertensive organ damage. In this review, we highlight recent advances in the potential contribution of gut microbiota alterations to myocardial interstitial fibrosis in hypertensive heart disease through blood pressure-dependent and blood pressure-independent mechanisms. Achievements in this field should open a new path for more comprehensive treatment of myocardial interstitial fibrosis in hypertensive heart disease and, thus, for the prevention of heart failure.

Immune cells crosstalk Pathways, and metabolic alterations in Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) presents a challenging progression characterized by lung tissue scarring and abnormal extracellular matrix deposition. This review examines the influence of immune responses, emphasizing their complex role in initiating and perpetuating fibrosis. It highlights how metabolic pathways modulate immune cell function during IPF. Immune cell modulation holds promise in managing pulmonary fibrosis (PF). Inhibiting neutrophil recruitment and monitoring mast cell levels offer insights into PF progression. Low-dose IL-2 therapy and regulation of fibroblast recruitment present potential therapeutic avenues, while the role of innate lymphoid cells (ILC2s) in allergic lung inflammation sheds light on disease mechanisms. The review focuses on metabolic reprogramming's role in shaping immune cell function during IPF progression. While some immune cells use glycolysis for pro-inflammatory responses, others favor fatty acid oxidation for regulatory functions. Targeting specialized pro-resolving lipid mediators (SPMs) presents significant potential for managing fibrotic disorders. Additionally, it highlights the pivotal role of amino acid metabolism in synthesizing serine and glycine as crucial regulators of collagen production and exploring the interconnectedness of lipid metabolism, mitochondrial dysfunction, and adipokines in driving fibrotic processes. Moreover, the review discusses the impact of metabolic disorders such as obesity and diabetes on lung fibrosis. Advocating for a holistic approach, it emphasizes the importance of considering this interplay between immune cell function and metabolic pathways in developing effective and personalized treatments for IPF.

Expression and diagnostic value of interleukin-22 in rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by a high incidence and mortality rate, highlighting the need for biomarkers to detect ILD early in RA patients. Previous studies have shown the protective effects of Interleukin-22 (IL-22) in pulmonary fibrosis using mouse models. This study aims to assess IL-22 expression in RA-ILD to validate foundational experiments and explore its diagnostic value. The study included 66 newly diagnosed RA patients (33 with ILD, 33 without ILD) and 14 healthy controls (HC). ELISA was utilized to measure IL-22 levels and perform intergroup comparisons. The correlation between IL-22 levels and the severity of RA-ILD was examined. Logistic regression analysis was employed to screen potential predictive factors for RA-ILD risk and establish a predictive nomogram. The diagnostic value of IL-22 in RA-ILD was assessed using ROC. Subsequently, the data were subjected to 30-fold cross-validation. IL-22 levels in the RA-ILD group were lower than in the RA-No-ILD group and were inversely correlated with the severity of RA-ILD. Logistic regression analysis identified IL-22, age, smoking history, anti-mutated citrullinated vimentin antibody (MCV-Ab), and mean corpuscular hemoglobin concentration (MCHC) as independent factors for distinguishing between the groups. The diagnostic value of IL-22 in RA-ILD was moderate (AUC = 0.75) and improved when combined with age, smoking history, MCV-Ab and MCHC (AUC = 0.97). After 30-fold cross-validation, the average AUC was 0.886. IL-22 expression is dysregulated in the pathogenesis of RA-ILD. This study highlights the potential of IL-22, along with other factors, as a valuable biomarker for assessing RA-ILD occurrence and progression.

A Novel Murine Model for Lupus-Like Ocular Chronic Graft-Versus-Host Disease

Purpose

Lupus-like chronic graft-versus-host disease (cGVHD) has been previously described, but the ocular findings have not been elucidated. Recipient mice in a lupus-like cGVHD model manifested notable and persistent ocular surface phenotypes. Herein, we further explored immunopathogenic mechanisms underlying these ocular phenotypes.

Methods

A previously described lupus-like cGVHD model was established by intraperitoneal injection of splenocytes from bm12 mice into C57BL/6J mice. Systemic findings were evaluated for the presence of splenomegaly, proteinuria, and autoantibodies. Comprehensive evaluations were conducted on ocular manifestations and immunopathological features in this model.

Results

The lupus-like cGVHD model was successfully constructed 2 weeks post-transplantation. The recipient mice developed lupus-like phenotypes, including splenomegaly, proteinuria, and increased autoantibodies, and their ocular presentations included corneal epithelial defects and decreased tear secretion. Histological analysis revealed a reduction in corneal nerve fiber density and corneal endothelial cells, along with conjunctival fibrosis and loss of goblet cells. Moreover, cGVHD induced progressive aggravation of immune cell infiltration and fibrosis in the lacrimal glands. RNA-Sequencing (RNA-seq) results of the lacrimal glands demonstrated that the differentially expressed genes (DEGs) between the control and cGVHD groups were associated with GVHD pathways. Immune infiltration analysis using RNA-seq and flow cytometry confirmed that CD8+ T lymphocytes predominantly constituted the inflammatory infiltrating cells within the lacrimal glands.

Conclusions

This lupus-like cGVHD model (bm12→C57BL/6J) exhibited persistent ocular surface manifestations, characterized by immune infiltration of CD8+ T lymphocytes in the lacrimal glands. Thus, this ocular cGVHD model may be used to explore the underlying mechanisms and discover novel therapeutic interventions.

Meta-analysis of the association between sex hormones and pulmonary fibrosis

BACKGROUND

This study aimed to investigate the association between sex hormones and the risk of pulmonary fibrosis by conducting a meta-analysis of previously published studies.

METHODS

We executed a comprehensive search of the PubMed, Embase, Cochrane Library, and Web of Science databases to locate pertinent studies published up to April 2024. We included studies that reported the association between sex hormones and the risk of pulmonary fibrosis. Standardized mean difference (SMD) with 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

A total of 10 articles, encompassing 1371 patients, were finally incorporated in this meta-analysis. Based on the evaluation of the included studies, it was observed that the levels of dehydroepiandrosterone sulfate (DHEA-S) (pooled SMD: -0.72, 95% CI: -1.21 to -0.24, p < 0.001), testosterone (pooled SMD: -1.25, CI: -2.39 and -0.11, p < 0.001) and estrogen (pooled SMD: -0.56, 95% CI: -0.96 to -0.15, p < 0.001) were significantly lower in patients with pulmonary fibrosis, whereas the levels of luteinizing hormone (LH) remained unaffected. Publication bias was ruled out through funnel plots.

CONCLUSION

This meta-analysis indicates that reduced levels of DHEA-S, testosterone, estrogen may serve as potential risk factors for pulmonary fibrosis. There is a pressing need for additional studies to confirm this association and explore the underlying biological mechanisms. Clinicians should recognize the potential influence of sex hormones in the etiology of pulmonary fibrosis and consider this aspect during the patient management process.

Are Endomyocardial Ventricular Biopsies Useful for Assessing Myocardial Fibrosis?

Myocardial fibrosis is an important factor in the progression of cardiovascular diseases. However, there is still no universal lifetime method of myocardial fibrosis assessment that has a high prognostic significance. The aim of the study was to determine the significance of ventricular endomyocardial biopsies for the assessment of myocardial fibrosis and to identify the severity of myocardial fibrosis in different cardiovascular diseases. Material and Methods: Endomyocardial biopsies (EMBs) of 20 patients with chronic lymphocytic myocarditis (CM), endomyocardial fragments obtained during septal reduction of 21 patients with hypertrophic cardiomyopathy (HCM), and 36 patients with a long history of hypertensive and ischemic heart disease (HHD + IHD) were included in the study. The control group was formed from EMBs taken on 12-14 days after heart transplantation (n = 28). Also, for one patient without clinical and morphological data for cardiovascular pathology, postmortem myocardial fragments were taken from typical EMB and septal reduction sites. The relative area of fibrosis was calculated as the ratio of the total area of collagen fibers to the area of the whole biopsy. Endocardium and subendocardial fibrosis were not included in the total biopsy area. Results: The relative fibrosis area in the EMBs in the CM patient group was 5.6 [3.3; 12.6]%, 11.1 [6.6; 15.9]% in the HHD + IHD patient group, 13.4 [8.8; 16.7]% in the HCM patient group, and 2.7 [1.5; 4.6]% in the control group. When comparing the fibrosis area of the CM patients in repeat EMBs, it was found that the fibrosis area in the first EMBs was 7.6 [4.8; 12.0]%, and in repeat EMBs, it was 5.3 [3.2; 7.6]%. No statistically significant differences were found between the primary and repeat EMBs (p = 0.15). In ROC analysis, the area of fibrosis in the myocardium of 1.1% (or lower than one) was found to be highly specific for the control group of patients compared to the study patients. Conclusions: EMB in the assessment of myocardial fibrosis has a questionable role because of the heterogeneity of fibrotic changes in the myocardium.

Determining toxicity of europium oxide nanoparticles in immune cell components and hematopoiesis in dominant organs in mice: Role of lysosomal fluid interaction

Extensive application of rare earth element oxide nanoparticles (REE NPs) has raised a concern over the possible toxic health effects after human exposure. Once entering the body, REE NPs are primarily processed by phagocytes in particular macrophages and undergo biotic phosphate complexation in lysosomal compartment. Such biotransformation affects the target organs and in vivo fate of REE NPs after escaping the lysosomes. However, the immunomodulatory effects of intraphagolysosomal dissolved REE NPs remains insufficient. Here, europium oxide (Eu2O3) NPs were pre-incubated with phagolysosomal simulant fluid (PSF) to mimic the biotransformation of europium oxide (p-Eu2O3) NPs under acid phagolysosome conditions. We investigated the alteration in immune cell components and the hematopoiesis disturbance on adult mice after intravenous administration of Eu2O3 NPs and p-Eu2O3 NPs. Our results indicated that the liver and spleen were the main target organs for Eu2O3 NPs and p-Eu2O3 NPs. Eu2O3 NPs had a much higher accumulative potential in organs than p-Eu2O3 NPs. Eu2O3 NPs induced more alterations in immune cells in the spleen, while p-Eu2O3 NPs caused stronger response in the liver. Regarding hematopoietic disruption, Eu2O3 NPs reduced platelets (PLTs) in peripheral blood, which might be related to the inhibited erythrocyte differentiation in the spleen. By contrast, p-Eu2O3 NPs did not cause significant disturbance in peripheral PLTs. Our study demonstrated that the preincubation with PSF led to a distinct response in the immune system compared to the pristine REE NPs, suggesting that the potentially toxic effects induced by the release of NPs after phagocytosis should not be neglected, especially when evaluating the safety of NPs application in vivo.

DEFB114 protein enhances host resistance to fungal infection through the NOD1/2-ATG16L1-NF-κB signaling pathway

The overuse of antibiotics has led to the enhanced resistance of many pathogenic bacteria, posing a threat to human health. Therefore, there is a need to develop green and safe alternatives to antibiotics. Beta-defensins play a crucial role in host defense against pathogens and have multifunctional properties, exerting key roles in innate and adaptive immunity, as well as non-immune processes. In this study, a 210 bp long cDNA sequence of yak DEFB114 gene was amplified and successfully expressed in a prokaryotic system. The DEFB114 protein exhibited significant inhibitory effects on the growth of Aspergillus fumigatus in vitro. When co-cultured with yak macrophages, DEFB114 protein enhanced macrophage phagocytic activity and increased nucleic acid fluorescence intensity (P < 0.05). DEFB114 protein also enhanced the activity of yak macrophages stimulated by inactivated Aspergillus fumigatus spores, increased the release of nitric oxide (NO), and promoted the expression of genes such as γ-actin, Lgals, Man2b, and Capg (P < 0.05). In mice experiments, DEFB114 protein promoted resistance against Aspergillus fumigatus infection, by regulating the NOD1/2-ATG16L1-NF-κB pathway to modulate the host immune response and exert its anti-infective effects. In summary, the yak DEFB114 protein could inhibit the growth of Aspergillus fumigatus and enhance the animal's resistance to pathogenic microorganisms, thereby having significant implications in the treatment and prevention of fungal infections.

Cell type-specific transforming growth factor-β (TGF-β) signaling in the regulation of salivary gland fibrosis and regeneration

Salivary gland damage and hypofunction result from various disorders, including autoimmune Sjögren's disease (SjD) and IgG4-related disease (IgG4-RD), as well as a side effect of radiotherapy for treating head and neck cancers. There are no therapeutic strategies to prevent the loss of salivary gland function in these disorders nor facilitate functional salivary gland regeneration. However, ongoing aquaporin-1 gene therapy trials to restore saliva flow show promise. To identify and develop novel therapeutic targets, we must better understand the cell-specific signaling processes involved in salivary gland regeneration. Transforming growth factor-β (TGF-β) signaling is essential to tissue fibrosis, a major endpoint in salivary gland degeneration, which develops in the salivary glands of patients with SjD, IgG4-RD, and radiation-induced damage. Though the deposition and remodeling of extracellular matrix proteins are essential to repair salivary gland damage, pathological fibrosis results in tissue hardening and chronic salivary gland dysfunction orchestrated by multiple cell types, including fibroblasts, myofibroblasts, endothelial cells, stromal cells, and lymphocytes, macrophages, and other immune cell populations. This review is focused on the role of TGF-β signaling in the development of salivary gland fibrosis and the potential for targeting TGF-β as a novel therapeutic approach to regenerate functional salivary glands. The studies presented highlight the divergent roles of TGF-β signaling in salivary gland development and dysfunction and illuminate specific cell populations in damaged or diseased salivary glands that mediate the effects of TGF-β. Overall, these studies strongly support the premise that blocking TGF-β signaling holds promise for the regeneration of functional salivary glands.

Plasma leucine-rich α-2 glycoprotein 1 in ST-elevation myocardial infarction: vertical variation, correlation with T helper 17/regulatory T ratio, and predictive value on major adverse cardiovascular events

Objective

Leucine-rich α-2 glycoprotein 1 (LRG1) promotes inflammation and myocardial injury, but its clinical role in ST-elevation myocardial infarction (STEMI) is rarely disclosed. Herein, this prospective study aimed to explore the value of plasma LRG1 at different time points to predict major adverse cardiovascular event (MACE) risk in patients with STEMI.

Methods

In total, 209 patients with STEMI were enrolled for determining plasma LRG1 at admission and on day (D)1/D7/D30 after admission via enzyme-linked immunosorbent assay, as well as for determination of peripheral blood T helper 17 (Th17) cells and regulatory T (Treg) cells by flow cytometry. In addition, plasma LRG1 was obtained from 30 healthy controls at enrollment.

Results

LRG1 was increased in patients with STEMI at admission compared with healthy controls (P < 0.001). In patients with STEMI, LRG1 varied at different time points (P < 0.001), which elevated from admission to D1, and gradually declined thereafter. LRG1 at admission was positively associated with Th17 cells (P = 0.001) and Th17/Treg ratio (P = 0.014). LRG1 at admission (P = 0.013), D1 (P = 0.034), D7 (P = 0.001), and D30 (P = 0.010) were increased in patients with MACE compared with those without. LRG1 at D7 exhibited good ability to estimate MACE risk (area under curve = 0.750, 95% confidence interval = 0.641-0.858). LRG1 at admission > 60 μg/ml (P = 0.031) and D7 > 60 μg/ml (P = 0.018) were linked with increased accumulating MACE. Importantly, LRG1 at D7 > 60 μg/ml was independently correlated with increased MACE risk (hazard ratio = 5.216, P = 0.033).

Conclusion

Plasma LRG1 increases from admission to D1 and gradually declines until D30, which positively links with Th17 cells and MACE risk in patients with STEMI.

Novel kinase 1 regulates CD8+T cells as a potential therapeutic mechanism for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a rare, chronic and progressively worsening lung disease that poses a significant threat to patient prognosis, with a mortality rate exceeding that of some common malignancies. Effective methods for early diagnosis and treatment remain for this condition are elusive. In our study, we used the GEO database to access second-generation sequencing data and associated clinical information from IPF patients. By utilizing bioinformatics techniques, we identified crucial disease-related genes and their biological functions, and characterized their expression patterns. Furthermore, we mapped out the immune landscape of IPF, which revealed potential roles for novel kinase 1 and CD8+T cells in disease progression and outcome. These findings can aid the development of new strategies for the clinical diagnosis and treatment of IPF.

Molecular Mechanisms Responsible for the Therapeutic Potential of Mesenchymal Stem Cell-Derived Exosomes in the Treatment of Lung Fibrosis

Mesenchymal stem cell-derived exosomes (MSC-Exos) are nano-sized extracellular vesicles which contain various MSC-sourced anti-fibrotic, immunoregulatory and angio-modulatory proteins (growth factors, immunoregulatory cytokines, chemokines), lipids, and nucleic acids (messenger RNA and microRNAs). Due to their lipid envelope, MSC-Exos easily by-pass all barriers in the body and deliver their cargo directly in target cells, modulating their viability, proliferation, phenotype and function. The results obtained in recently published experimental studies demonstrated beneficial effects of MSC-Exos in the treatment of lung fibrosis. MSC-Exos reduced activation of fibroblasts and prevented their differentiation in myofibroblasts. By delivering MSC-sourced immunoregulatory factors in lung-infiltrated monocytes and T cells, MSC-Exos modulate their function, alleviating on-going inflammation and fibrosis. MSC-Exos may also serve as vehicles for the target delivery of anti-fibrotic and immunomodulatory agents, enabling enhanced attenuation of lung fibrosis. Although numerous pre-clinical studies have demonstrated the therapeutic potential of MSC-Exos in the treatment of pulmonary fibrosis, there are several challenges that currently hinder their clinical implementation. Therefore, in this review article, we summarized current knowledge and we discussed future perspectives regarding molecular and cellular mechanisms which were responsible for the anti-fibrotic, anti-inflammatory and immunoregulatory properties of MSC-Exos, paving the way for their clinical use in the treatment of lung fibrosis.

Alterations in peripheral T- and B-cell subsets in patients with systemic sclerosis

OBJECTIVES

To determine the alteration of peripheral T and B cell subsets in patients with systemic sclerosis (SSc) and to evaluate their correlation with the progression of SSc.

METHODS

We recruited 47 SSc patients and 45 healthy controls (HCs) in this study. Demographic and clinical data were then collected. Flow cytometry was used to detect the proportions of 44 different T and B cell subsets in circulating blood.

RESULTS

The proportion of total B cells (p = .043) decreased in SSc patients, together with similar frequencies of total T cells, CD4+ T cells, and CD8+ T cells in both groups. Several subsets of T and B cells differed significantly between these two groups. Follicular helper T cells-1 (Tfh1) (p < .001), helper T cells-1 (Th1) (p = .001), regulatory T cells (Treg) (p = .004), effector memory CD8+ T cells (p = .041), and cytotoxic T cells-17 (Tc17) (p = .01) were decreased in SSc patients. Follicular helper T cells-2 (Tfh2) (p = .001) and, helper T cells-2 (Th2) (p = .001) levels increased in the SSc group. Regulatory B cells (Breg) (p = .015) were lower in the SSc group, together with marginal zone (MZ) B cells (p < .001), memory B cells (p = .001), and non-switched B cells (p = .005). The modified Rodnan skin score (mRSS) correlated with helper T cells-17 (Th17) (r = -.410, p = .004), Tfh1 (r = -.321, p = .028), peripheral helper T cells (Tph) (r = -.364, p = .012) and plasma cells (r = -.312, p = .033).

CONCLUSIONS

The alterations in T and B cells implied immune dysfunction, which may play an essential role in systemic sclerosis.

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Yin Yang 1 facilitates the activation, inflammation, and extracellular matrix deposition of hepatic stellate cells in hepatic fibrosis

Chronic hepatic diseases often involve fibrosis as a pivotal factor in their progression. This study investigates the regulatory mechanisms of Yin Yang 1 (YY1) in hepatic fibrosis. Our data reveal that YY1 binds to the prolyl hydroxylase domain 1 (PHD1) promoter. Rats treated with carbon tetrachloride (CCl4) display heightened fibrosis in liver tissues, accompanied by increased levels of YY1, PHD1, and the fibrosis marker alpha-smooth muscle actin (α-SMA). Elevated levels of YY1, PHD1, and α-SMA are observed in the liver tissues of CCl4-treated rats, primary hepatic stellate cells (HSCs) isolated from fibrotic liver tissues, and transforming growth factor beta-1 (TGF-β1)-induced HSCs. The human HSC cell line LX-2, upon YY1 overexpression, exhibits enhanced TGF-β1-induced activation, leading to increased expression of extracellular matrix (ECM)-related proteins and inflammatory cytokines. YY1 silencing produces the opposite effect. YY1 exerts a positive regulatory effect on the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and PHD1 expression. PHD1 silencing rescues the promotion of YY1 in cell activation, ECM-related protein expression, and inflammatory cytokine production in TGF-β1-treated LX-2 cells. Overall, our findings propose a model wherein YY1 facilitates TGF-β1-induced HSC activation, ECM-related protein expression, and inflammatory cytokine production by promoting PHD1 expression and activating the PI3K/AKT signaling pathway. This study positions YY1 as a promising therapeutic target for hepatic fibrosis.

Biology of neurofibrosis with focus on multiple sclerosis

Tissue damage elicits a wound healing response of inflammation and remodeling aimed at restoring homeostasis. Dysregulation of wound healing leads to accumulation of effector cells and extracellular matrix (ECM) components, collectively termed fibrosis, which impairs organ functions. Fibrosis of the central nervous system, neurofibrosis, is a major contributor to the lack of neural regeneration and it involves fibroblasts, microglia/macrophages and astrocytes, and their deposited ECM. Neurofibrosis occurs commonly across neurological conditions. This review describes processes of wound healing and fibrosis in tissues in general, and in multiple sclerosis in particular, and considers approaches to ameliorate neurofibrosis to enhance neural recovery.

Cardiac fibrogenesis: an immuno-metabolic perspective

Cardiac fibrosis is a major and complex pathophysiological process that ultimately culminates in cardiac dysfunction and heart failure. This phenomenon includes not only the replacement of the damaged tissue by a fibrotic scar produced by activated fibroblasts/myofibroblasts but also a spatiotemporal alteration of the structural, biochemical, and biomechanical parameters in the ventricular wall, eliciting a reactive remodeling process. Though mechanical stress, post-infarct homeostatic imbalances, and neurohormonal activation are classically attributed to cardiac fibrosis, emerging evidence that supports the roles of immune system modulation, inflammation, and metabolic dysregulation in the initiation and progression of cardiac fibrogenesis has been reported. Adaptive changes, immune cell phenoconversions, and metabolic shifts in the cardiac nonmyocyte population provide initial protection, but persistent altered metabolic demand eventually contributes to adverse remodeling of the heart. Altered energy metabolism, mitochondrial dysfunction, various immune cells, immune mediators, and cross-talks between the immune cells and cardiomyocytes play crucial roles in orchestrating the transdifferentiation of fibroblasts and ensuing fibrotic remodeling of the heart. Manipulation of the metabolic plasticity, fibroblast-myofibroblast transition, and modulation of the immune response may hold promise for favorably modulating the fibrotic response following different cardiovascular pathological processes. Although the immunologic and metabolic perspectives of fibrosis in the heart are being reported in the literature, they lack a comprehensive sketch bridging these two arenas and illustrating the synchrony between them. This review aims to provide a comprehensive overview of the intricate relationship between different cardiac immune cells and metabolic pathways as well as summarizes the current understanding of the involvement of immune-metabolic pathways in cardiac fibrosis and attempts to identify some of the previously unaddressed questions that require further investigation. Moreover, the potential therapeutic strategies and emerging pharmacological interventions, including immune and metabolic modulators, that show promise in preventing or attenuating cardiac fibrosis and restoring cardiac function will be discussed.

Effects of Nanomaterials on Synthesis and Degradation of the Extracellular Matrix

Extracellular matrix (ECM) remodeling is accompanied by the continuous synthesis and degradation of the ECM components. This dynamic process plays an important role in guiding cell adhesion, migration, proliferation, and differentiation, as well as in tissue development, body repair, and maintenance of homeostasis. Nanomaterials, due to their photoelectric and catalytic properties and special structure, have garnered much attention in biomedical fields for use in processes such as tissue engineering and disease treatment. Nanomaterials can reshape the cell microenvironment by changing the synthesis and degradation of ECM-related proteins, thereby indirectly changing the behavior of the surrounding cells. This review focuses on the regulatory role of nanomaterials in the process of cell synthesis of different ECM-related proteins and extracellular protease. We discuss influencing factors and possible related mechanisms of nanomaterials in ECM remodeling, which may provide different insights into the design and development of nanomaterials for the treatment of ECM disorder-related diseases.

Role of Treg cell subsets in cardiovascular disease pathogenesis and potential therapeutic targets

In the genesis and progression of cardiovascular diseases involving both innate and adaptive immune responses, inflammation plays a pivotal and dual role. Studies in experimental animals indicate that certain immune responses are protective, while others exacerbate the disease. T-helper (Th) 1 cell immune responses are recognized as key drivers of inflammatory progression in cardiovascular diseases. Consequently, the CD4+CD25+FOXP3+ regulatory T cells (Tregs) are gaining increasing attention for their roles in inflammation and immune regulation. Given the critical role of Tregs in maintaining immune-inflammatory balance and homeostasis, abnormalities in their generation or function might lead to aberrant immune responses, thereby initiating pathological changes. Numerous preclinical studies and clinical trials have unveiled the central role of Tregs in cardiovascular diseases, such as atherosclerosis. Here, we review the roles and mechanisms of Treg subsets in cardiovascular conditions like atherosclerosis, hypertension, myocardial infarction and remodeling, myocarditis, dilated cardiomyopathy, and heart failure. While the precise molecular mechanisms of Tregs in cardiac protection remain elusive, therapeutic strategies targeting Tregs present a promising new direction for the prevention and treatment of cardiovascular diseases.

Higher densities of T-lymphocytes in the subsynovial connective tissue of people with carpal tunnel syndrome

Symptoms in people with carpal tunnel syndrome (CTS) are traditionally attributed to neural tissue, but recent studies suggest that the subsynovial connective tissue (SSCT) may also play a role in CTS. The SSCT undergoes fibrotic thickening which is generally described as "non-inflammatory" based on basic histology. This study uses immunohistochemistry to determine the presence of macrophages and T-cells within SSCT and their relationship with symptoms in people with CTS. SSCT was collected from twenty people with CTS and eight controls undergoing wrist fracture surgery. Immunohistochemical quantification of CD3+ T-cells and CD68+ macrophage densities as well as CD4+/CD8+ T-cell subpopulations were compared between groups using independent t-tests. Spearman correlations were used to identify associations between immune cell densities and CTS symptom scores. The density of CD3+ T-cells was significantly higher in SSCT of people with CTS compared to controls (CTS mean 26.7 (SD 13.7); controls 6.78 (6.3), p = 0.0005) while the density of CD68+ macrophages was lower (CTS mean 9.5 (SD 6.0); controls 17.7 (8.2), p = 0.0058). Neither CD68+ nor CD3+ cell densities correlated with symptom scores. In contrast to previous assumptions, our data show that the SSCT in the carpal tunnel in both people with CTS and controls is not devoid of immune cells. Whereas the higher density of CD68+ macrophages in control participants may be associated with their early recruitment after acute fracture, CD3+ cells within the SSCT may play a role in chronic CTS.

Increased CD8+ tissue resident memory T cells, regulatory T cells and activated natural killer cells in systemic sclerosis lungs

OBJECTIVE

Multiple observations indicate a role for lymphocytes in driving autoimmunity in SSc. While T and NK cells have been studied in SSc whole blood and bronchoalveolar lavage fluid, their role remains unclear, partly because no studies have analysed these cell types in SSc-interstitial lung disease (ILD) lung tissue. This research aimed to identify and analyse the lymphoid subpopulations in SSc-ILD lung explants.

METHODS

Lymphoid populations from 13 SSc-ILD and 6 healthy control (HC) lung explants were analysed using Seurat following single-cell RNA sequencing. Lymphoid clusters were identified by their differential gene expression. Absolute cell numbers and cell proportions in each cluster were compared between cohorts. Additional analyses were performed using pathway analysis, pseudotime and cell ligand-receptor interactions.

RESULTS

Activated CD16+ NK cells, CD8+ tissue resident memory T cells and Treg cells were proportionately higher in SSc-ILD compared with HC lungs. Activated CD16+ NK cells in SSc-ILD showed upregulated granzyme B, IFN-γ and CD226. Amphiregulin, highly upregulated by NK cells, was predicted to interact with epidermal growth factor receptor on several bronchial epithelial cell populations. Shifts in CD8+ T cell populations indicated a transition from resting to effector to tissue resident phenotypes in SSc-ILD.

CONCLUSIONS

SSc-ILD lungs show activated lymphoid populations. Activated cytotoxic NK cells suggest they may kill alveolar epithelial cells, while their expression of amphiregulin suggests they may also induce bronchial epithelial cell hyperplasia. CD8+ T cells in SSc-ILD appear to transition from resting to the tissue resident memory phenotype.

Imbalance of TH17/TREG cells in Tunisian patients with systemic sclerosis

Fibrosis is a pathological manifestation in which connective tissue replaces normal one. It can affect many tissues from the skin to internal organs such as the lungs. Manifestations of pulmonary involvement can be pulmonary arterial hypertension or pulmonary fibrosis. The latter one is currently the leading cause of death in various autoimmune diseases, including systemic sclerosis. Our study group consists of 50 patients with systemic sclerosis: 24 with limited cutaneous form and 26 with diffuse cutaneous form. This cohort was compared to 50 healthy controls (age and sex matched); our aim is to explore the distribution of TH17 cells (TH17) as well as regulatory T cells (TREG) and study their correlation with the disease's progress. Our results show an increase for IL17A in patients compared to controls and that this increase is correlated with a specific clinical involvement: Pulmonary fibrosis. This correlation suggests a crucial role of IL17A in fibrosis especially in systemic sclerosis. In addition, we have shown that the percentages of TH17 cells are higher in patients; however, the percentages of TREG cells are similar between patients and controls. A study of TREG cell activity showed that TREG lost suppressive activity by inactivating the FOXP3 transcription factor. This proves that despite their presence, TREG does not adequately carry out their regulatory activity. Finally, we analyzed the correlation between TH17/TREG and clinical damage; the results show a positive correlation with pulmonary involvement proving the role of TH17/TREG balance in induced fibrosis in systemic sclerosis. No significative difference was observed, for all the parameters, between the two different forms of the disease. In conclusion, the results associated with the TH17/TREG scale and their correlations with fibrosis in systemic sclerosis open a way for new tools to manage this autoimmune disease, which up to today has neither treatment nor accurate diagnosis.

Antifibrotic activity of carbon quantum dots in a human in vitro model of non-alcoholic steatohepatitis using hepatic stellate cells

Around 33% of the global population suffers from non-alcoholic fatty liver disease (NAFLD). From these patients, 30% of them progress into non-alcoholic steatohepatitis (NASH), the critical point where lack of treatment leads to cirrhosis and hepatic failure. Moreover, to date, there are no approved therapeutic options available for NASH. It is known that hepatic stellate cell (HSC) activation contributes the most to hepatic disfunction, leading to reactive oxygen species (ROS) accumulation and chronic inflammation, and that the use of nanomaterials to deliver antioxidants may have potential to reduce the activity of activated HSCs. Therefore, we implemented a human in vitro co-culture model in which we take into consideration two factors related to NASH and fibrosis: human hepatic stellate cells from a NASH diagnosed donor (HHSC-N) and peripheral blood mononuclear cells (PBMCs), particularly lymphocytes. The co-cultures were treated with: (1) carbon quantum dots (CD) or (2) lactoferrin conjugated CD (CD-LF) for 24 h or 72 h. CD and CD-LF treatments significantly downregulated profibrotic genes' expression levels of ACTA2, COL1A1, and TIMP1 in co-cultured HHSC-N at 72 h. Also, we assayed the inflammatory response by quantifying the concentrations of cytokines IL-22, IL-10, IFN-γ and IL-4 present in the co-culture's conditioned media whose concentrations may suggest a resolution-associated response in progress. Our findings may serve as a starting point for the development of a NASH treatment using bio-nanotechnology.

Periodontitis aggravates COPD through the activation of γδ T cell and M2 macrophage

Chronic obstructive pulmonary disease (COPD) is a chronic systemic inflammatory disease with high morbidity and mortality. Periodontitis exacerbates COPD progression; however, the immune mechanisms by which periodontitis affects COPD remain unclear. Here, by constructing periodontitis and COPD mouse models, we demonstrated that periodontitis and COPD could mutually aggravate disease progression. For the first time, we found that the progression was associated with the activation of γδ T cells and M2 macrophages, and M2 polarization of macrophages was affected by γδ T cells activation. In the lung tissues of COPD with periodontitis, the activation of γδ T cells finally led to the increase of IL 17 and IFN γ expression and M2 macrophage polarization. Furthermore, we found that the periodontitis-associated bacteria Porphyromonas gingivalis (P. gingivalis) promoted the activation of γδ T cells and M2 macrophages ex vivo. The data from clinical bronchoalveolar lavage fluid (BALF) samples were consistent with the in vivo and ex vivo experiments. For the first time, our results identified the crucial role of γδ T-M2 immune mechanism in mediating periodontitis-promoted COPD progression. Therefore, targeting at periodontitis treatment and the γδ T-M2 immune mechanism might provide a new practical strategy for COPD prevention or control.IMPORTANCEPeriodontitis exacerbates chronic obstructive pulmonary disease (COPD) progression. For the first time, the current study identified that the impact of periodontitis on COPD progression was associated with the activation of γδ T cells and M2 macrophages and that M2 polarization of macrophages was affected by γδ T cells activation. The results indicated that targeting at periodontitis treatment and the γδ T-M2 immune mechanism might provide a new practical strategy for COPD prevention or control.

Bone Formation and Maintenance in Oral Surgery: The Decisive Role of the Immune System-A Narrative Review of Mechanisms and Solutions

Based on the evidence of a significant communication and connection pathway between the bone and immune systems, a new science has emerged: osteoimmunology. Indeed, the immune system has a considerable impact on bone health and diseases, as well as on bone formation during grafts and its stability over time. Chronic inflammation induces the excessive production of oxidants. An imbalance between the levels of oxidants and antioxidants is called oxidative stress. This physio-pathological state causes both molecular and cellular damage, which leads to DNA alterations, genetic mutations and cell apoptosis, and thus, impaired immunity followed by delayed or compromised wound healing. Oxidative stress levels experienced by the body affect bone regeneration and maintenance around teeth and dental implants. As the immune system and bone remodeling are interconnected, bone loss is a consequence of immune dysregulation. Therefore, oral tissue deficiencies such as periodontitis and peri-implantitis should be regarded as immune diseases. Bone management strategies should include both biological and surgical solutions. These protocols tend to improve immunity through antioxidant production to enhance bone formation and prevent bone loss. This narrative review aims to highlight the relationship between inflammation, oxidation, immunity and bone health in the oral cavity. It intends to help clinicians to detect high-risk situations in oral surgery and to propose biological and clinical solutions that will enhance patients' immune responses and surgical treatment outcomes.

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.

Stromal Cell Regulation of Intestinal Inflammatory Fibrosis

Intestinal inflammatory fibrosis is a severe consequence of inflammatory bowel diseases (IBDs). There is currently no cure for the treatment of intestinal fibrosis in IBD. Although inflammation is necessary for triggering fibrosis, the anti-inflammatory agents used to treat IBD are ineffective in preventing the progression of intestinal fibrosis and stricture formation once initiated, suggesting that inflammatory signals are not the sole drivers of fibrosis progression once it is established. Among multiple mechanisms involved in the initiation and progression of intestinal fibrosis in IBD, stromal cells play critical roles in mediating the process. In this review, we summarize recent progress on how stromal cells regulate intestinal fibrosis in IBD and how they are regulated by focusing on immune regulation and gut microbiota. We also outline the challenges moving forward in the field.

Subpopulation composition of blood T-helpers in hepatitis C patients with genotype 1 or 3

Introduction. Despite advances in treatment, the problem of chronic viral hepatitis C (CVHC) remains very relevant for Russia. There is a debate about which of the most common genotypes in our country: 1 or 3, has a more aggressive course of CVHC. Patients with CVHC exhibit dysfunction of T-cell immunity, many aspects of which remain unclear.

Aim. To research the subpopulation composition of blood T-helpers in patients with genotypes 1 and 3 of chronic viral hepatitis C (CVHC) depending on the severity of clinical and morphological manifestations.

Materials and methods. Clinical, laboratory examination and determination of liver fibrosis by elastometry using the METAVIR scale were performed in 297 patients with CVHC genotype 1, 231 patients with CVHC genotype 3, and 20 healthy individuals in the control group. The study of the subpopulation composition of T-helpers in the blood by flow cytometry (Navios, Beckman Coulter, USA) with the determination of markers CD3, CD4, CD45R0 and CD62L was carried out in 74 patients with CVHC genotype 1, 70 patients with CVHC genotype 3 and 20 people in the control group.

Results. Naive T-helpers (CD3+CD4+CD45RO-CD62L+), T-helpers of central (CD3+CD4+CD45R0+CD62L+) and effector memory (CD3+CD4+CD45R0+CD62L–) in the blood decreased with an increase in the severity of fibrosis and inflammation activity in the liver in both examined groups. In patients with CVHC genotype 3, the content of TEMRA T-helpers (CD3+CD4+CD45R0-CD62L-) in the blood under these conditions sharply decreased (Kruskal – Wallis test, respectively, p = 0.04 and p = 0.02). In patients with CVHC genotype 1, no such patterns were registered (Kruskal – Wallis test, respectively, p = 0.8 and p = 0.87).

Conclusion. A direct correlation was determined between the deterioration of the indicators of the blood T-helpers subpopulation composition with an increase in the severity of fibrosis and inflammation activity in the liver in patients with chronic hepatitis C, which had some differences in patients with genotypes 1 and 3.