The Important Role of the Chemokine Axis CCR7-CCL19 and CCR7-CCL21 in the Pathophysiology of the Immuno-inflammatory Response in Dry Eye Disease

A large hypothesis-free proteomics study investigating serum inflammatory markers as biomarkers of dry eye disease

PURPOSE

To test the association between serum inflammatory markers and dry eye disease (DED) using a hypothesis-free proteomic approach in a population-based cohort.

METHODS

A total of 2602 unselected community-based participants (mean age 61.5 (range 21-92 years), 94.4 % female) from the TwinsUK cohort were examined. DED was assessed with the validated Women's Health Study (WHS) questionnaire; cases were defined by either a previous clinician diagnosis or presence of highly symptomatic dry eye. Serum inflammatory markers were assessed with the Olink Target 96 Inflammation panel. We performed logistic regression mixed effect models, adjusted for age, BMI, sex, and twin relatedness, with false discovery rate (FDR) correction.

RESULTS

Prevalence of WHS-defined DED was 29.1 %, with 26.2 % having a previous diagnosis of DED and 16.5 % having highly symptomatic dry eye. Of 74 inflammatory markers, significant associations with WHS-defined DED were found for neurotrophin-3 (NT-3; OR: 0.68, FDR p-value: 0.043), natural killer-cell receptor 2B4 (CD244; OR: 0.68, FDR p-value: 0.043), C-X-C motif chemokines (CXCL) 9 (OR: 1.23, FDR p-value: 0.043) and CXCL10 (OR: 1.22, FDR p-value: 0.043). Significant association with highly symptomatic dry eye were found with increased levels of CCL19, CXCL9, CXCL10, CCL20, CX3CL1 (fractalkine), TNF, CDCP1, and CCL25.

CONCLUSIONS

This large population-based study found several serum inflammatory proteins to be associated with DED, confirming and adding to previous targeted tear and corneal and conjunctival expression studies in murine models and clinic-based case-control studies. Of interest, a novel potential biomarker NT-3, which plays a role in corneal nerve function, was identified.

Inflammatory profiling and immune cell infiltration in dysthyroid optic neuropathy: insights from bulk RNA sequencing

Background

Dysthyroid optic neuropathy (DON), the most severe complication of thyroid eye disease (TED), has unclear mechanisms and unsatisfactory treatment outcomes. This study aimed to identify key pathways and inflammation-related core genes driving DON progression, potentially informing new therapeutic strategies and improving disease management.

Methods

Retro-orbital tissues from DON, non-DON TED, and healthy controls (HCs) were analyzed using bulk RNA sequencing. Differentially expressed genes (DEGs) were identified and subjected to Gene Ontology (GO) enrichment analysis. Weighted gene co-expression network analysis (WGCNA) identified disease-relevant modules. Immune cell infiltration was assessed via single-sample Gene Set Enrichment Analysis (ssGSEA). ROC analysis and single-gene GSEA were used to evaluate the diagnostic potential and functional relevance of core genes. Inflammatory-Related Differential Genes (IRDGS) were identified and preliminarily validated using Quantitative Real-Time PCR.

Results

Differential gene expression analysis revealed 176 and 202 significantly upregulated genes in DON vs. non-DON and DON vs. HCs comparisons, respectively. Notably, inflammation-related genes, including CXCL14, CCL21, HP, and fibrosis-associated genes such as MGP, FN1, and COL11A1, were significantly upregulated in DON group. GO enrichment analyses identified immune-related processes like lymphocyte proliferation, cytokine activity, and extracellular matrix remodeling. WGCNA further identified key gene modules associated with inflammation and tissue remodeling in DON, and IRDCGs, such as CCL21, HP, and SLCO2A1, emerged as the most significant markers. Single-gene GSEA confirmed that these genes are involved in immune response, inflammation, and fibrosis-related processes. Immune cell infiltration analysis using ssGSEA revealed that DON patients exhibited significantly increased infiltration of activated B cells, CD4 T cells, mast cells, and Th1 cells, and correlation analysis showed that IRDGs were significantly associated with multiple immune cell types, particularly activated B cells and regulatory T cells. Finally, qPCR validation of the top 10 IRDEGs in retro-orbital tissues showed that HP, TPSAB1, and PLA2G2A were significantly upregulated in the DON.

Conclusions

This is the first study to identify the key molecular and immune drivers of DON through bulk transcriptomic analysis, emphasizing the central role of inflammation-related molecules and immune cell infiltration in its pathogenesis. The identified IRDGs and their associated pathways provide novel insights for innovative diagnostic and therapeutic strategies.

Dupilumab-associated ocular surface disease is characterized by a shift from Th2/Th17 toward Th1/Th17 inflammation

BACKGROUND

Dupilumab is used for the treatment of atopic dermatitis (AD). Approximately one third of AD patients develop a dupilumab-associated ocular surface disease (DAOSD), of which the pathomechanism is poorly understood. This study aimed at investigating inflammatory markers in tear fluids of patients on dupilumab therapy.

METHODS

Tear fluids were collected from AD patients with DAOSD (ADwDAOSD), AD patients without DAOSD (ADw/oDAOSD), and non-AD patients before and during dupilumab therapy, and analyzed using a specialized proteomic approach quantifying inflammatory markers. The ocular surface microbiome was determined by next generation sequencing technology.

RESULTS

Upon dupilumab therapy, an upregulation of 31 inflammatory markers was observed in DAOSD tear fluids compared to baseline in AD patients. While IL-12B was upregulated in both ADwDAOSD and ADw/oDAOSD groups, the pattern of inflammatory markers significantly differed between groups and over time. In the ADwDAOSD group, a shift from a mixed Th2/Th17 pattern at baseline toward a Th1/Th17 profile under dupilumab was observed. Furthermore, an upregulation of remodeling and fibrosis markers was seen in DAOSD. Semantic map and hierarchical cluster analyses of baseline marker expression revealed four clusters distinguishing between AD and non-AD as well as ADwDAOSD and ADw/oDAOSD patient groups. In a pilot study, dupilumab therapy was associated with a decrease in richness of the ocular surface microbiome.

CONCLUSIONS

DAOSD is characterized by a Th1/Th17 cytokine profile and an upregulation of markers known to promote remodeling and fibrosis. The expression pattern of inflammatory markers in tear fluids at baseline might serve as a prognostic factor for DAOSD.

New targets of nascent lymphatic vessels in ocular diseases

Recent advancements in the field of endothelial markers of lymphatic vessels and lymphangiogenic factors have shed light on the association between several ocular diseases and ocular nascent lymphatic vessels. The immune privilege of corneal tissue typically limits the formation of lymphatic vessels in a healthy eye. However, vessels in the eyes can potentially undergo lymphangiogenesis and be conditionally activated. It is evident that nascent lymphatic vessels in the eyes contribute to various ocular pathologies. Conversely, lymphatic vessels are present in the corneal limbus, ciliary body, lacrimal glands, optic nerve sheaths, and extraocular muscles, while a lymphatic vasculature-like system exists in the choroid, that can potentially cause several ocular pathologies. Moreover, numerous studies indicate that many ocular diseases can influence or activate nascent lymphatic vessels, ultimately affecting patient prognosis. By understanding the mechanisms underlying the onset, development, and regression of ocular nascent lymphatic vessels, as well as exploring related research on ocular diseases, this article aims to offer novel perspectives for the treatment of such conditions.

Effects of chemokine receptor CCR7 in the pathophysiology and clinical features of the immuno-inflammatory response in primary pterygium

OBJECTIVE

Chemokine receptor 7 (CCR7) has been considered a critical biomarker in inflammation and the immune response; however, little is known about CCR7 in pterygia. This study aimed to investigate whether CCR7 participates in the pathogenesis of primary pterygia and how CCR7 affects the progression of pterygia.

METHODS

This was an experimental study. Slip-lamp photographs of 85 pterygium patients were used to measure the width, extent, and area of pterygia with computer software. Pterygium blood vessels and general ocular redness were quantitatively analyzed with a specific algorithm. The expression of CCR7 and its ligands C-C motif ligand 19 (CCL19) and C-C motif ligand 21 (CCL21) in control conjunctivae and excised pterygia collected during surgery were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescence staining. The phenotype of CCR7-expressing cells was identified by costaining for major histocompatibility complex II (MHC II), CD11b or CD11c.

RESULTS

The CCR7 level was significantly increased by 9.6-fold in pterygia compared with control conjunctivae (p = 0.008). The higher the expression of CCR7 was, the more blood vessels appeared in pterygia (r = 0.437, p = 0.002) and the more general ocular redness was (r = 0.51, p < 0.001) in pterygium patients. CCR7 was significantly associated with pterygium extent (r = 0.286, p = 0.048). In addition, we found that CCR7 colocalized with CD11b, CD11c or MHC II in dendritic cells, and immunofluorescence staining showed that CCR7-CCL21 is a potential chemokine axis in pterygium.

CONCLUSIONS

This work verified that CCR7 impacts the extent of primary pterygia invading the cornea and inflammation at the ocular surface, which may provide a possibility for a further in-depth understanding of the immunological mechanism in pterygia.

Relationship between dry eye and expressions of CXCR3 and CCR5 after ocular acid burn

OBJECTIVE

To investigate the manifestation of dry eye and its relationship with CXCR3 and CCR5 expression in patients with ocular acid burns.

METHODS

This is a case-control study. A total of 27 eyes of 22 cases ocular with acid burns of I-V degrees from Jan.2020 to Feb.2021 in Jinshan Hospital of Fudan University were selected as observation group, and 8 eyes of 8 cases of normal people were selected as control group. The follow-up period was 3 months. The visual acuity, intraocular pressure (IOP), corneal fluorescein staining scores (CFS), breakup time of tear film (BUT), Schirmer I test, corneal thickness and tear meniscus height (TMH) were observed at 1 day, 1 and 3 months after injury. The protein expressions of CXCR3 and CCR5 were examined by ELISA and compared among groups at each time point.

RESULTS

BUT and Schirmer I tests value in the observation group were lower than those in the control group 3 months after injury (BUT: Group I ~ IV p = 0.0266, p = 0.0222, p = 0.0003, p = 0.0059, respectively; Schirmer I test: Group I ~ IV p = 0.0027, p = 0.0033, p = 0.0016, p = 0.0032, respectively). CFS scores were higher than those in the control group at 1 day after injury (all p < 0.0001), but decreased gradually at 1 and 3 months after injury (Group I ~ IV p = 0.0042, p = 0.0096, p < 0.0001, p < 0.0001, respectively). The corneal thickness and TMH 1 day after injury were higher than those in the control group (corneal thickness: Group II ~ IV p = 0.0010, p < 0.0001, p < 0.0001, respectively; TMH: Group II ~ IV p = 0.0002, p < 0.0001, p < 0.0001, respectively), and also higher than those at 1 month and 3 months after injury (corneal thickness: Group II ~ IV p = 0.0010, p < 0.0001, p < 0.0001, respectively; TMH: Group II ~ IV p = 0.0345 and p = 0.0045, p = 0.0005 and p < 0.0001, p = 0.0114 and p = 0.0019, respectively). The expression levels of CXCR3 and CCR5 protein were significantly negatively correlated with BUT (all p < 0.0001), and CXCR3 and CCR5 were also significantly negatively correlated with Schirmer I test value (p < 0.0001, p = 0.0004, respectively).

CONCLUSION

Ocular acid burns can cause dry eye, and the expression of CXCR3 and CCR5 protein in tears may be related to the occurrence of dry eye after ocular acid burn.

The Role of Neutrophil Extracellular Traps in the Ocular System

Purpose: Neutrophils remain at the top of congenital and adaptive immune systems. The past 20 years witnessed a steep rise in the interest in neutrophil extracellular traps (NETs), which are a novel type of anti-pathogen mechanism coordinated with neutrophils. However, accumulating data revealed that excessive NETs in the host were associated with exacerbated inflammation, thrombosis, and autoimmunity. Increasing evidence found the participation of NETs in the pathophysiological process of many infectious and sterile diseases in the ocular system. Therefore, we discussed the role of neutrophil extracellular traps in the ocular system in this review.Methods: Articles were searched on PubMed, Embase and Web of science up to December 2021.Results: In this review, we exhibited the protective role of neutrophils patrolling the ocular surface from invading pathogens and their contribution to exacerbated inflammation and thrombogenesis in some ocular diseases. We also discussed the physiological and pathological processes of NET generation to identify novel biomarkers and therapeutic targets to interrupt immoderate NET formation and alleviate NET-induced harmful effects.Conclusions: Neutrophils and NETs are quite important for immune responses in the ocular system, while their negative effects on ocular tissue should also be emphasized, which could serve as novel biomarkers and potential therapeutic targets.

Comprehensive Genetic Analysis of Tuberculosis and Identification of Candidate Biomarkers

Purpose: The purpose of this study is to use the data in the GEO database to analyze, screen biomarkers that can diagnose tuberculosis, and verification of candidate biomarkers.

Materials and methods: GSE158767 dataset were used to process WGCNA analysis, differential gene analysis, Gene ontology and KEGG analysis, protein-protein network analysis and hub genes analysis. Based on our previous study, the intersect between WGCNA and differential gene analysis could be used as candidate biomarkers. Then, the enzyme-linked immunosorbent assay was used to validate candidate biomarkers, and receiver operating characteristic was used to assess diagnose ability of candidate biomarkers.

Results: A total of 412 differential genes were screened. And we obtained 105 overlapping genes between DEGs and WGCNA. GO and KEGG analysis showed that most of the differential genes were significantly enriched in innate immunity. A total of 15 hub genes were screened, and four of them were verified by Enzyme-linked immunosorbent assay. CCL5 performed well in distinguishing the healthy group from the TB group (AUC = 0.723). And CCL19 performed well in distinguishing the TB group from the ORD groups (AUC = 0.811).

Conclusion: CCL19, C1Qb, CCL5 and HLA-DMB may play important role in tuberculosis, which indicated four genes may become effective biomarkers and could be conveniently used to facilitate the individual tuberculosis diagnosis in Chinese people.

New Insights of CCR7 Signaling in Dendritic Cell Migration and Inflammatory Diseases

CCR7, collaborated with its ligands CCL19 and CCL21, controls extensive migratory events in the immune system. CCR7-bearing dendritic cells can swarm into T-cell zones in lymph nodes, initiating the antigen presentation and T-cell response. Abnormal expression of CCR7 in dendritic cells will cause a series of inflammatory diseases due to the chaotic dendritic cell trafficking. In this review, we take an in-depth look at the structural–functional domains of CCR7 and CCR7-bearing dendritic cell trajectory to lymph nodes. Then, we summarize the regulatory network of CCR7, including transcriptional regulation, translational and posttranslational regulation, internalization, desensitization, and recycling. Furthermore, the potential strategies of targeting the CCR7 network to regulate dendritic cell migration and to deal with inflammatory diseases are integrated, which not only emphasizes the possibility of CCR7 to be a potential target of immunotherapy but also has an implication on the homing of dendritic cells to benefit inflammatory diseases.

The link module of human TSG-6 (Link_TSG6) promotes wound healing, suppresses inflammation and improves glandular function in mouse models of Dry Eye Disease

PURPOSE

To investigate the potential of the Link_TSG6 polypeptide comprising the Link module of human TSG-6 (TNF-stimulated gene/protein-6) as a novel treatment for dry eye disease (DED).

METHODS

We analyzed the therapeutic effects of topical application of Link_TSG6 in two murine models of DED, the NOD.B10.H2^b mouse model and the desiccating stress model. The effects of Link_TSG6 on the ocular surface and DED were compared with those of full-length TSG-6 (FL_TSG6) and of 0.05% cyclosporine (Restasis®). Additionally, the direct effect of Link_TSG6 on wound healing of the corneal epithelium was evaluated in a mouse model of corneal epithelial debridement.

RESULTS

Topical Link_TSG6 administration dose-dependently reduced corneal epithelial defects in DED mice while increasing tear production and conjunctival goblet cell density. At the highest dose, no corneal lesions remained in ∼50% of eyes treated. Also, Link_TSG6 significantly suppressed the levels of inflammatory cytokines at the ocular surface and inhibited the infiltration of T cells in the lacrimal glands and draining lymph nodes. Link_TSG6 was more effective in decreasing corneal epithelial defects than an equimolar concentration of FL_TSG6. Link_TSG6 was significantly more potent than Restasis® at ameliorating clinical signs and reducing inflammation. Link_TSG6 markedly and rapidly facilitated epithelial healing in mice with corneal epithelial debridement wounds.

CONCLUSION

Link_TSG6 holds promise as a novel therapeutic agent for DED through its effects on the promotion of corneal epithelial healing and tear secretion, the preservation of conjunctival goblet cells and the suppression of inflammation.

Autoimmunity in dry eye disease - An updated review of evidence on effector and memory Th17 cells in disease pathogenicity

The classic Th1/Th2 dogma has been significantly reshaped since the subsequent introduction of several new T helper cell subsets, among which the most intensively investigated during the last decade is the Th17 lineage that demonstrates critical pathogenic roles in autoimmunity and chronic inflammation - including the highly prevalent dry eye disease. In this review, we summarize current concepts of Th17-mediated disruption of ocular surface immune homeostasis that leads to autoimmune inflammatory dry eye disease, by discussing the induction, activation, differentiation, migration, and function of effector Th17 cells in disease development, highlighting the phenotypic and functional plasticity of Th17 lineage throughout the disease initiation, perpetuation and sustention. Furthermore, we emphasize the most recent advance in Th17 memory formation and function in the chronic course of dry eye disease, a major area to be better understood for facilitating the development of effective treatments in a broader field of autoimmune diseases that usually present a chronic course with recurrent episodes of flare in the target tissues or organs.

Screening of Biological Target Molecules Related to Glucocorticoid-Induced Cataract (GIC) on the Basis of Constructing ceRNA Network

Glucocorticoid-induced cataract (GIC)-associated biomarkers were screened by ceRNA network construction. The GIC samples' GSE3040 were obtained from the NCBI-GEO database. R's Limma package was used to identify differentially expressed RNAs (DERs) between the normal and GIC samples group (4- and 16-h). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis for the mRNAs in the constructed GIC lncRNA-miRNA-mRNA ceRNA regulation network was implemented. A total of 1665 and 1443 DERs were obtained in the 4- and 16-h group, respectively. At two time points, 256 overlapping DERs were identified, of which 210 (17 lncRNAs and 203 mRNAs) had significant differential expression (4 down- and 206 up-regulated). A total of 534 co-expressed ligation pairs (all up-regulated) were obtained. A ceRNA regulation network was constructed. RPS6KA5, GAB1, CCR7, CCL2, COL4A4, and PPARG were obtained and significantly enriched in the 4 KEGG signaling pathways and were featured as GIC target molecules.

Regulation of the Migration of Distinct Dendritic Cell Subsets

Dendritic cells (DCs), a class of antigen-presenting cells, are widely present in tissues and apparatuses of the body, and their ability to migrate is key for the initiation of immune activation and tolerogenic immune responses. The importance of DCs migration for their differentiation, phenotypic states, and immunologic functions has attracted widespread attention. In this review, we discussed and compared the chemokines, membrane molecules, and migration patterns of conventional DCs, plasmocytoid DCs, and recently proposed DC subgroups. We also review the promoters and inhibitors that affect DCs migration, including the hypoxia microenvironment, tumor microenvironment, inflammatory factors, and pathogenic microorganisms. Further understanding of the migration mechanisms and regulatory factors of DC subgroups provides new insights for the treatment of diseases, such as infection, tumors, and vaccine preparation.