Potentially pathogenic immune cells and networks in apparently healthy lacrimal glands

Bibliometric and visualized analysis of research hotpots and future prospects in lacrimal duct obstruction disease (1900 to 2024)

AIM

To reveal the research hotspots, trends, and future prospects of lacrimal duct obstruction disease (LDOD) from 1900 to 2024 through the bibliometric and visualized analysis, providing a directional guidance for research in this field.

METHODS

The Web of Science Core Collection database was used to retrieve relevant literature. Data analysis and visualization were conducted using VOSviewer 1.6.20 and CiteSpace 6.3.1, including annual publication volume, trends, research areas, country/region and institution distribution, journal and co-cited journal analysis, author and co-cited author analysis, keyword and burst keyword analysis, etc.

RESULTS

The study included a total of 1481 articles, revealing an overall upward trend in research on LDOD, with ophthalmology being the predominant field. While the United States previously led research efforts, India and China have emerged as key contributors since 2015. Mohammad Javed Ali stands out as the most influential author in this research area. Ophthalmic Plastic and Reconstructive Surgery has published the highest number of related articles, whereas Ophthalmology has the highest co-citation. The current focal points of research include minimally invasive and precise modifications to dacryocystorhinostomy, along with intubation, new materials for stents, and disease pathogenesis.

CONCLUSION

LDOD research has garnered widely attention and exhibits a steady upward trend. Since 1900, the United States, China, and India have been the leading contributors to this field. Ophthalmologists continue to be the primary driving force behind LDOD research. The findings of this study suggest that at the forefront of LDOD research, our focus has long been on refining and innovating surgical treatment. The minimally invasive and precise modification of lacrimal surgery, represented by dacryocystorhinostomy, is the ongoing developmental direction of this field. Rapid interdisciplinary integration and in-depth exploration of pathogenesis and allergic inflammation will lead to the emergence of new materials, innovative technologies, and safer clinical treatment protocols.

[Cell technologies as a basis for the development of regenerative principles for the treatment of lacrimal gland diseases]

The lacrimal gland (LG) is a tubuloacinar exocrine gland composed of acinar, ductal, and myoepithelial cells. Three-dimensional distribution of acinar lobules, ducts, and myoepithelial cells is necessary for the effective functioning of the organ. LG is the main organ of immune surveillance of the ocular surface system. The embryogenesis of the gland is regulated by the interaction of genetic mechanisms, internal epigenetic (enzyme systems, hormones) and exogenous factors. There is no doubt that there is a clear genetic program for the implementation of the complex process of embryonic development. The mechanisms regulating LG organogenesis initiate the work of a huge number of structural oncogenes, transcription and growth factors, etc. Studying the expression and selective activity of regulatory genes during organ development, their participation in the differentiation of different cell types is a current trend at the nexus of clinical genetics, molecular biology, embryology and immunocytochemistry. Due to its relatively simple structure and accessibility, human LG is a suitable object for potential application in regenerative medicine. Development of a universal protocol for obtaining functional differentiated secretory epithelium of LG capable of expressing tissue-specific markers is an urgent task. Determining the nature and origin of stem cells and progenitor cells will allow the isolation and multiplication of these cells in culture. After obtaining a functionally active culture of LG cells, it is possible to create a model of autoimmune diseases.

High-Fat Nutritional Challenge Reshapes Circadian Signatures in Murine Extraorbital Lacrimal Glands

Purpose

A high-fat diet (HFD) increases the risk of developing many systemic diseases; however, the effects of high fat intake on lacrimal gland functions and the molecular mechanisms underlying these effects are unknown. We explored the effects of an HFD on the circadian rhythms of the extraorbital lacrimal glands (ELGs).

Methods

Male C57BL/6J mice maintained on a 12/12-hour light/dark cycle were fed an ad libitum HFD or normal chow (NC) for 2 weeks. The ELGs were collected from euthanized animals every 3 hours throughout the circadian cycle (24 hours). Using high-throughput RNA-sequencing (RNA-Seq), we studied the circadian transcriptomic profile of the ELGs. Circadian oscillations in cell size, secretion response, lipid deposition, and immune cell trafficking of the ELGs were also analyzed.

Results

An HFD modulated the circadian transcriptomic profile of the ELGs, including the composition, phase, and amplitude of cyclical transcript oscillations, and affected the associated signaling pathways at spatiotemporal levels. HFD feeding significantly altered the normal rhythmic oscillations of ELG cell size, immune cell trafficking, secretion response, and lipid deposition. After dietary reversal in HFD-fed animals, the activity, core temperature, and lipid accumulation in lacrimal glands recovered partially to the level of NC-fed animals. However, the average cell size of the ELGs, the recruitment of immune cells, and the rhythm of lacrimal secretion did not return to the levels of the NC-fed group.

Conclusions

HFD perturbation interferes with the cyclical transcriptomic profile, cell size, immune cell trafficking, and secretion function of the ELGs with a strikingly high sensitivity.

Molecular Evidence for Precursors of Sjögren's Foci in Histologically Normal Lacrimal Glands

Understanding the formation of Sjogren’s lymphocytic infiltrates could permit earlier diagnosis and better outcomes. We submitted gene transcript abundances in histologically normal rabbit lacrimal glands to principal component analysis. The analysis identified a cluster of transcripts associated with Sjögren’s foci, including messenger RNAs (mRNAs) for C–X–C motif chemokine ligand 13 (CXCL13) and B-cell activating factor (BAFF), which dominated the major principal component. We interpreted the transcript cluster as the signature of a cluster of integrally functioning cells. Pregnancy and dryness increased the likelihood that the cluster would develop to high levels, but responses were subject to high levels of stochasticity. Analyzing microdissected samples from high- and low-cluster-level glands, we found that certain transcripts, including mRNAs for C–C motif chemokine ligand 21 (CCL21), CXCL13, cluster of differentiation 4 (CD4), CD28, CD25, BAFF, and interleukin 18 (IL-18) were significantly more abundant in immune cell clusters (ICs) from the high-cluster-level gland; mRNAs for CCL2, CD25, and IL-1RA were significantly more abundant in acinus-duct axis samples; mRNAs for CCL4, BAFF, IL-6, and IL-10 were more abundant in some acinus-duct samples; cells with high prolactin immunoreactivity were more frequent in interacinar spaces. In conclusion, integrated functional networks comprising Sjögren’s infiltrates, such as ICs, acinar cells, ductal cells, and interacinar cells, can form in histologically normal glands, and it is feasible to detect their molecular signatures.

Pregnancy probabilistically augments potential precursors to chronic, immune-mediated or autoimmune lacrimal gland infiltrates

PURPOSE

This study asked whether pregnancy, a risk factor for dry eye disease associated with both chronic, immune-mediated- and autoimmune etiologies, augments development of clusters of coordinately functioning cells (CCFC) that may be precursors to pathological lacrimal gland infiltrates.

METHODS

Lacrimal glands were from six virgin- and six term-pregnant rabbits of the same age and environmental exposure history. Seventy-two immune response-related gene transcripts were assayed by real time RT-PCR. Principal component (PC) analysis identified transcript signatures of CCFC contributing negative (^⊖) or positive (^⊕) PC loadings and determined gland PC projections, which reflect levels of CCFC development.

RESULTS

Three CCFC were of interest as potential precursors to pathological infiltrates. CCFC 1^⊖ was suggestive of an ectopic lymphoid structure with resting T cells and B cells. CCFC 1^⊕ was suggestive of an immune-mediated infiltrate with T_H1 cells and mature, cytotoxic B cells. CCFC 2^⊖ was suggestive of an ectopic lymphoid structure with activated T cells, mature B cells, germinal center, and plasmacytes. CCFC 4^⊖ and CCFC 5^⊖ also included plasmacytes. Pregnancy augmented CCFC 1^⊖ in some glands; augmented CCFC 1^⊕ in others; and augmented CCFC 2^⊖, CCFC 4^⊖, and CCFC 5^⊖ different combinations.

CONCLUSIONS

Potential precursors of pathological infiltrates form in the lacrimal glands by the time of sexual maturity. Pregnancy augments lacrimal gland plasmacyte populations, and it can augment development of potential precursors to either chronic, immune-mediated infiltrates or autoimmune infiltrates of various phenotypes. Systemic and strictly local, probabilistic phenomena interact with pregnancy to determine which combinatorial phenotypes are favored.

Multiple Natural and Experimental Inflammatory Rabbit Lacrimal Gland Phenotypes

Purpose

To investigate lacrimal gland (LG) immunophysiological and immune-mediated inflammatory process (IMIP) phenotype diversity.

Methods

Ex vivo matured dendritic cells (mDC) were loaded with acinar cell microparticles (M_P). Peripheral blood lymphocytes (PBL) were activated in mixed cell reactions with mDC and injected directly into autologous, unilateral LG (1° ATD-LG) of two rabbit cohorts, one naïve, one immunized with a LG lysate membrane fraction (P_i). Autoimmune IgG titers were assayed by ELISA, MCR PBL stimulation indices (SI) by [³H]-thymidine incorporation. Schirmer tests without and with topical anesthetic (STT-I, STT-I_A) and rose Bengal (RB) staining tests were performed. H&E and immunohistochemically stained sections were examined. RNA yields and selected transcript abundances were measured. Immune cell number and transcript abundance data were submitted to Principal Component Analysis (PCA).

Results

Immunizing P_i dose influenced SI but not IgG titers. STT scores were decreased, and rose Bengal scores increased, by day 118 after immunization. Previous immunization exacerbated scores in 1° ATD-eyes and exacerbated 1° ATD-LG atrophy. IMIP were evident in 2° ATD-LG as well as 1° ATD-LG. PCA described diverse immunophysiological phenotypes in control LG and diverse IMIP phenotypes in ATD-LG. IgG titers and SI pre-adoptive transfer were significantly associated with certain post-adoptive transfer IMIP phenotype features, and certain LG IMIP features were significantly associated with RB and STT I_A scores.

Conclusions

The underlying variability of normal states may contribute to the diversity of experimental IMIP phenotypes. The ability to generate and characterize diverse phenotypes may lead to phenotype-specific diagnostic and therapeutic paradigms.

Orbital Inflammation in Pregnant Women

OBJECTIVE

To analyze overlaps between pregnancy and orbital inflammation (OI).

DESIGN

Retrospective observational case series.

METHODS

Eight new cases from 1997 to 2015 and 2 previously published cases were identified for inclusion in this investigation to provide the fullest clinical picture. Medical records, imaging studies, and the results of biopsies were reviewed.

RESULTS

Three categories of association were discovered: (1) OI arising for the first time during pregnancy (5 cases); (2) OI arising within 3 months of delivery (2 cases); and (3) previously diagnosed OI reactivated or exacerbated by pregnancy (3 cases). One patient had a preexistent systemic autoimmune disease and another's was later diagnosed. One patient had attacks during sequential pregnancies. Findings included eyelid swelling and erythema, conjunctival chemosis, pain on eye movement, minimal diplopia, the usual absence of proptosis, and general preservation of visual acuity. Imaging studies disclosed extraocular muscle swelling (8 cases), most frequently of a single lateral rectus muscle. There were 2 cases of dacryoadenitis; 1 of these and an additional case displayed inflammation of the retrobulbar fat. Corticosteroids effected resolution of most symptoms. Singleton births were normal with the exceptions of an intrauterine fetal demise owing to acrania and a molar pregnancy.

CONCLUSION

OI usually affects a single rectus muscle (typically the lateral) and, less often, the lacrimal gland and is often mild when it arises during or after pregnancy. Independent systemic autoimmune disease is an uncommon feature. Corticosteroids were efficacious except in 1 case with severe orbital scarring. No definitive causal relationships between pregnancy and OI could be established based on the clinical data.