Identification of Autoimmunity to Peptides of Collagen V α1 Chain as Newly Biomarkers of Early Stage of Systemic Sclerosis

Type V collagen-induced nasal tolerance prevents lung damage in an experimental model: new evidence of autoimmunity to collagen V in COPD

Background

Chronic obstructive pulmonary disease (COPD) has been linked to immune responses to lung-associated self-antigens. Exposure to cigarette smoke (CS), the main cause of COPD, causes chronic lung inflammation, resulting in pulmonary matrix (ECM) damage. This tissue breakdown exposes collagen V (Col V), an antigen typically hidden from the immune system, which could trigger an autoimmune response. Col V autoimmunity has been linked to several lung diseases, and the induction of immune tolerance can mitigate some of these diseases. Evidence suggests that autoimmunity to Col V might also occur in COPD; thus, immunotolerance to Col V could be a novel therapeutic approach.

Objective

The role of autoimmunity against collagen V in COPD development was investigated by analyzing the effects of Col V-induced tolerance on the inflammatory response and lung remodeling in a murine model of CS-induced COPD.

Methods

Male C57BL/6 mice were divided into three groups: one exposed to CS for four weeks, one previously tolerated for Col V and exposed to CS for four weeks, and one kept in clean air for the same period. Then, we proceeded with lung functional and structural evaluation, assessing inflammatory cells in bronchoalveolar lavage fluid (BALF) and inflammatory markers in the lung parenchyma, inflammatory cytokines in lung and spleen homogenates, and T-cell phenotyping in the spleen.

Results

CS exposure altered the structure of elastic and collagen fibers and increased the pro-inflammatory immune response, indicating the presence of COPD. Col V tolerance inhibited the onset of emphysema and prevented structural changes in lung ECM fibers by promoting an immunosuppressive microenvironment in the lung and inducing Treg cell differentiation.

Conclusion

Induction of nasal tolerance to Col V can prevent inflammatory responses and lung remodeling in experimental COPD, suggesting that autoimmunity to Col V plays a role in COPD development.

A Positive Feedback Loop Exists between Estradiol and IL-6 and Contributes to Dermal Fibrosis

Systemic sclerosis (SSc) is characterized by dermal fibrosis with a female predominance, suggesting a hormonal influence. Patients with SSc have elevated interleukin (IL)-6 levels, and post-menopausal women and older men also have high estradiol (E2) levels. In the skin, IL-6 increases the enzymatic activity of aromatase, thereby amplifying the conversion of testosterone to E2. Therefore, we hypothesized that an interplay between E2 and IL-6 contributes to dermal fibrosis. We used primary dermal fibroblasts from healthy donors and patients with diffuse cutaneous (dc)SSc, and healthy donor skin tissues stimulated with recombinant IL-6 and its soluble receptor (sIL-6R) or E2. Primary human dermal fibroblasts and tissues from healthy donors stimulated with IL-6+sIL-6R produced E2, while E2-stimulated dermal tissues and fibroblasts produced IL-6. Primary dermal fibroblasts from healthy donors treated with IL-6+sIL-6R and the aromatase inhibitor anastrozole (ANA) and dcSSc fibroblasts treated with ANA produced less fibronectin (FN), type III collagen A1 (Col IIIA1), and type V collagen A1 (Col VA1). Finally, dcSSc dermal fibroblasts treated with the estrogen receptor inhibitor fulvestrant also generated less FN, Col IIIA1, and Col VA1. Our data show that IL-6 exerts its pro-fibrotic influence in human skin in part through E2 and establish a positive feedback loop between E2 and IL-6.

Identification and validation of targets of swertiamarin on idiopathic pulmonary fibrosis through bioinformatics and molecular docking-based approach

BACKGROUND

Swertiamarin is the main hepatoprotective component of Swertiapatens and has anti-inflammatory and antioxidation effects. Our previous study showed that it was a potent inhibitor of idiopathic pulmonary fibrosis (IPF) and can regulate the expressions of α-smooth muscle actin (α-SMA) and epithelial cadherin (E-cadherin), two markers of the TGF-β/Smad (transforming growth factor beta/suppressor of mothers against decapentaplegic family) signaling pathway. But its targets still need to be investigated. The main purpose of this study is to identify the targets of swertiamarin.

METHODS

GEO2R was used to analyze the differentially expressed genes (DEGs) of GSE10667, GSE110147, and GSE71351 datasets from the Gene Expression Omnibus (GEO) database. The DEGs were then enriched with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis for their biological functions and annotated terms. The protein-protein interaction (PPI) network was constructed to identify hub genes. The identified hub genes were predicted for their bindings to swertiamarin by molecular docking (MD) and validated by experiments.

RESULTS

76 upregulated and 27 downregulated DEGs were screened out. The DEGs were enriched in the biological function of cellular component (CC) and 7 cancer-related signaling pathways. Three hub genes, i.e., LOX (lysyl oxidase), COL5A2 (collagen type V alpha 2 chain), and CTGF (connective tissue growth factor) were selected, virtually tested for the interactions with swertiamarin by MD, and validated by in vitro experiments.

CONCLUSION

LOX, COL5A2, and CTGF were identified as the targets of swertiamarin on IPF.

The Hypoxia-Related Gene COL5A1 Is a Prognostic and Immunological Biomarker for Multiple Human Tumors

Background

Collagen type V alpha 1 chain (COL5A1) is a hypoxia-related gene (a collagen family protein) and participates in the formation of the extracellular matrix. Although some evidence supports a significant role for COL5A1 in the progression of several cancers, a pan-cancer analysis of COL5A1 is not currently available. Herein, we aimed to assess the prognostic value of COL5A1 in 33 human cancers and to investigate its underlying immunological function.

Methods

Through multiple bioinformatics methods, we analyzed the data from Oncomine, TCGA, CCLE, HPA, DNMIVD, and cBioPortal database to explore the potential underlying carcinogenic effect of COL5A1, including the relevance of COL5A1 to the outcome, DNA methylation, tumor microenvironment, immune cells infiltration, and drug sensitivity in 33 human cancers. The effects of COL5A1 on glioma cell proliferation, migration, and invasion were verified in cellular experiments.

Results

Our findings indicated that COL5A1 was expressed at high levels in 13 cancers and was negatively related to the prognosis of 11 cancers. Additionally, COL5A1 was coexpressed with genes encoding the major histocompatibility complex, immune activators, immune suppressors, chemokines, chemokine receptors, mismatch repair genes, and immune checkpoints. We also identified different roles for COL5A1 in the immunocyte infiltration in different cancers. The correlation between COL5A1 and drug sensitivity was found in several cancers. COL5A1 potentially influenced the tumor progression through immune-related pathways, negative regulation of immune system processes, chemokine signaling pathways, JAK-STAT pathways, T cell receptor pathways, lymphocyte migration, and antigen processing and presentation, among other processes.

Conclusions

Based on our study, COL5A1 may be employed as a prognostic marker in different malignancies because of its impact on tumorigenesis and immune cell infiltration and have implications for cancer immune checkpoint inhibitors and chemotherapy.

Insights into origins and specificities of autoantibodies in systemic sclerosis

PURPOSE OF REVIEW

Autoantibodies are hallmark findings in systemic sclerosis (SSc), often present prior to disease onset. Clinical diagnosis and prognosis of SSc have long relied on the antitopoisomerase - anticentromere - anti-RNA polymerase antibody trichotomy. However, many more autoantibodies found in SSc are being actively investigated for insights into triggering events, mechanisms of tolerance break, and connections to tissue damage. This review examines recent studies on SSc autoantibodies and the early events that lead to their development.

RECENT FINDINGS

Recent work has elucidated potential connections between human cytomegalovirus infection, silicone breast implants, and malignancy to SSc autoantibody development. At the level of the dendritic cell:T cell interaction, where tolerance is broken, new studies identified shared motifs in the peptide-binding domains of SSc-associated human leukocyte antigen alleles. Immunological analysis of SSc patient B cells has uncovered several anomalies in the regulatory capacities of SSc naïve and memory B cell populations. Expanding efforts to uncover new SSc autoantibodies revealed anti-CXCL4, anticollagen V, and other autoantibodies as potential players in disease pathogenesis.

SUMMARY

Further research into the role of autoantibodies in SSc development may uncover new mechanism-guided therapeutic targets. In addition, a better understanding of autoantibody associations with SSc disease outcomes will improve clinical care.