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

Hyperprolactinemia modifies extracellular matrix components associated with collagen fibrillogenesis in harderian glands of non- and pregnant female mice

The harderian gland (HG) is a gland located at the base of the nictating membrane and fills the inferomedial aspect of the orbit in rodents. It is under the influence of the hypothalamic-pituitary-gonadal axis and, because of its hormone receptors, it is a target tissue for prolactin (PRL) and sex steroid hormones (estrogen and progesterone). In humans and murine, the anterior surface of the eyes is protected by a tear film synthesized by glands associated with the eye. In order to understand the endocrine changes caused by hyperprolactinemia in the glands responsible for the formation of the tear film, we used an animal model with metoclopramide-induced hyperprolactinemia (HPRL). Given the evidences that HPRL can lead to a process of cell death and tissue fibrosis, the protein expression of small leucine-rich proteoglycans (SLRPs) was analyzed through immunohistochemistry in the HG of the non- and the pregnant female mice with hyperprolactinemia. The SRLPs are related to collagen fibrillogenesis and they participate in pro-apoptotic signals. Our data revealed that high prolactin levels and changes in steroid hormones (estrogen and progesterone) can lead to an alteration in the amount of collagen, and in the structure of type I and III collagen fibers through changes in the amounts of lumican and decorin, which are responsible for collagen fibrillogenesis. This fact can lead to the impaired functioning of the HG by excessive apoptosis in the HG of the non- and the pregnant female mice with HPRL and especially in the HG of pregnancy-associated hyperprolactinemia.

CCL21/CCR7 axis as a therapeutic target for autoimmune diseases

Chemokine receptor 7 (CCR7) is a G protein-coupled receptor containing 7 transmembrane domains that is expressed on various cells, such as naive T/B cells, central memory T cells, regulatory T cells, immature/mature dendritic cells (DCs), natural killer cells, and a minority of tumor cells. Chemokine ligand 21 (CCL21) is the known high-affinity ligand that binds to CCR7 and drives cell migration in tissues. CCL21 is mainly produced by stromal cells and lymphatic endothelial cells, and its expression is significantly increased under inflammatory conditions. Genome-wide association studies (GWAS) have shown a strong association between CCL21/CCR7 axis and disease severity in patients with rheumatoid arthritis, sjogren's syndrome, systemic lupus erythematosus, polymyositis, ankylosing spondylitis, and asthma. Disrupting CCL21/CCR7 interaction with antibodies or inhibitors prevents the migration of CCR7-expressing immune and non-immune cells at the site of inflammation and reduces disease severity. This review emphasizes the importance of the CCL21 /CCR7 axis in autoimmune diseases and evaluates its potential as a novel therapeutic target for these conditions.

Association Between Vitamin D and Minor Salivary Gland Inflammation

Objective There has been increasing research regarding the effects of vitamin D on autoimmune disorders. There is some evidence of a correlation between vitamin D levels and sicca symptoms. We attempted to evaluate the correlation between vitamin D levels and inflammation of the minor salivary gland (MSG). Methods Data for 214 patients who had undergone MSG biopsy were reviewed. Eighteen patients with other autoimmune/neoplastic processes were excluded. Seventy-seven of 196 patients had serum Vitamin D levels available and were selected for this retrospective study. Demographic, clinical, and immunological features, extra-glandular manifestations, autoantibodies, and clinical laboratory tests were collected and compared between patient groups with a focus score (FS) of 0 and 1 or more. Results Out of 77, 29 patients had an FS of 0 while 48 had an FS of 1 or more. Mean vitamin D levels were noted to be lower in patients with an FS of 1 when compared to patients with an FS of 1 or more. Conclusion In this study, patients with an FS of 1 were noted to have low vitamin D levels but this association was not seen at a higher FS.

Mechanisms of Disease in Sjögren Syndrome-New Developments and Directions

Sjögren Syndrome (SS) is an autoimmune disease that affects the exocrine glands, mainly salivary and lacrimal glands [...].