Abdelhamid, S. | Search bioRxiv

bioRxiv2026

Tear Proteomics Reveals RAGE and NLRP3 Inflammasome Pathway Activation in Lacrimal Glands of a Sjögren's Disease Mouse Model

PurposeTo characterize tear proteome changes in male non-obese diabetic (NOD) mice with Sjogrens disease (SjD)-like autoimmune dacryoadenitis and determine whether identified tear proteins are associated with lacrimal gland (LG) pathogenesis. MethodsTears were collected from 14-week-old male NOD mice and age-matched male BALB/c controls and analyzed by tandem mass tag (TMT)-based liquid chromatography tandem mass spectrometry (LC-MS/MS). Differentially expressed proteins (DEPs) were defined using adjusted P < 0.05 and absolute fold change > 1.5. Functional enrichment analysis was performed using Enrichr. Selected upregulated DEPs were further examined in tear and LG samples from independent mouse cohorts using Western blotting, immunofluorescence, and RT-qPCR. ResultsA total of 142 proteins were quantified across all tear samples. Hierarchical clustering and principal component analysis (PCA) separated NOD from BALB/c tear proteomes. A total of 41 proteins were differentially expressed in NOD mouse tears (33 increased, 8 decreased). Increased tear proteins were enriched in immune and inflammatory responses, secretory compartments, RAGE receptor binding, glutathione metabolism, oxidative stress, and redox regulation. S100A8/A9, GSTO1-1, Gal-3, and pIgR/secretory component (SC) were increased in both NOD mouse tears and LG. In NOD LG, increased S100A8/A9 was accompanied by elevated RAGE, whereas increased GSTO1-1 was associated with increased NLRP3, cleaved caspase-1, cleaved gasdermin, cleaved IL-1{beta}, and increased Il1b, Il18, and Il18r gene expression. ConclusionsMale NOD mouse tears contain disease-related proteins reflecting pathological inflammatory and epithelial changes in the LG including increased RAGE signaling, NLRP3 inflammasome activation, and altered epithelial transcytosis.

immunology↗

bioRxiv2024

Serum and Tear Autoantibodies from NOD and NOR Mice as Potential Diagnostic Indicators of Local and Systemic Inflammation in Sjögren's Disease

BackgroundSjogrens Disease (SjD) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands (LG). The LG produces the protein-rich aqueous component of tears, and SjD-associated autoimmune dacryoadenitis (AD) may thus alter tear autoantibody composition. MethodsThe presence of tertiary lymphoid structures (TLS) in LG from two murine models of SjD-associated AD, male NOD and male NOR mice, were evaluated using immunofluorescence. IgG and IgA reactivity in serum and tears from these models were probed in three studies against a panel of 80-120 autoantigens using autoantibody microarrays relative to serum and tears from healthy male BALB/c mice. Data were analyzed by R package Limma. ResultsAnalysis of immunofluorescence in LG sections from both SjD models showed TLS. Only one autoantibody was significantly elevated in tears and serum in both SjD models across all studies. Three autoantibodies were significantly elevated in serum but not in tears in both SjD models across all studies. Conversely, six IgG and thirteen IgA autoantibodies (6 sharing the same autoantigen) were significantly elevated in tears but not serum in both SjD models. ConclusionNOD and NOR mice with SjD-associated AD have distinct autoantibody profiles in tears and serum. Tear IgA isotype autoantibodies showed a greater diversity than tear IgG autoantibodies. TLS observed in LG are a likely source of the tear autoantibodies.

immunology↗