The study aimed to characterize the expression and function of SFTA3

The study aimed to characterize the expression and function of SFTA3 at the ocular surface and in tears. closure rate and rSFTA3 reduced the surface tension of tear fluid. The results indicate that SFTA3 at the ocular surface seemed to be involved in wound healing and the reduction of surface tension. Introduction In Central Europe, about 15% to 20% of the human population are suffering from dry vision disease (DED, keratoconjunctivitis sicca). Exogenous influences (e.g. contact lenses, air, drugs, diet) and endogenous factors (e.g. age, hormonal imbalances, diabetes mellitus) are the main causes of this disease. DED is based upon a discontinuity of the tear film1 (DEWS Statement 2007) characterized by cardinal symptoms like burning, Rabbit Polyclonal to OR8S1 itchy and watery eyes, painful vision pressure, oppressive feeling, foreign body sensations and light sensitivity. In almost 86% DED is the result of a diminished outer lipid layer at the surface of the tear film2, a condition called evaporative DED. A quantitative deficit of tears, on the other hand, is considered to be less common. The lipid component of the tear film is mainly secreted by the meibomian glands of the eyelids. Under physiological conditions, the lipid component prevents evaporation and early break-up of the tear film and thus, protects the eye surface3. Together with the lacrimal glands and accessory lacrimal glands of the eyelids which produce the aqueous component of the tear film, meibomian secretions (meibum) generate a barrier against pathogenic microorganisms4. A further component of the tear film comprises proteins of the surfactant family (SP-A, -B, -C buy SJN 2511 and CD) buy SJN 2511 that are well known from your lung and have previously also been explained at the eye surface, in tear film and in the lacrimal gland5C7. In the lung surfactant proteins regulate surface activity and have immunological properties with regard to both adaptive and innate immunity8C10. Recently, two novel surfactant proteins SFTA2 (SP-G)11 and SFTA3 (SP-H)12 were recognized and characterized. SP-G has physicochemical properties similar to the already explained proteins SP-B and SP-C. Moreover, the ability to interact with lipid systems combined with a potential surface-regulatory function of SP-G has been discussed. Surfactant-associated protein 3 (SFTA 3) was first recognized by bioinformatic analyses and named surfactant protein H (SP-H) or SFTA313. This protein shows no significant sequential or structural similarities with other surfactant proteins or other known proteins in general. The proposed physicochemical properties of SFTA3 show similarities with the well-characterized surfactant proteins B and C. Molecular dynamic (MD) simulations and protein modeling analyses suggest that SFTA3 may constitute a surface-active material. Despite the absence of known structurally conserved immune regulatory domains SFTA3 might still play a possible role in the immune defense and during inflammation processes12. Stimulation experiments with a lung epithelial cell collection (A549) revealed that SFTA3 gene expression is significantly influenced by the presence of immunomodulating cytokines (IL-1 and IL-23) as well as bacterial lipopolysaccharide (LPS)12. In a dose-effect analysis with IL-1 and IL-23 a reduced expression of SFTA3 was shown, while buy SJN 2511 LPS induced SFTA3 expression. It was hypothesized that LPS simultaneously triggers the production of inflammatory cytokines like IL-1 and IL-23 production in resident alveolar macrophages and SFTA3 induction via TLR in alveolar epithelial buy SJN 2511 cells. Thus, gram-negative bacterial infection apparently promotes the SFTA3 pathway in alveolar epithelial cells, whereas inflammatory cytokines like IL-1 and IL-23 secreted by alveolar macrophages apparently limit this process12. A recent study around the impact of recombinant SFTA3 protein on alveolar macrophages showed an increased phagocytosis rate, suggesting a possible immunological function of the protein inside the lung14. In the present study we investigated whether SFTA3 is also part of the tissues of the human ocular surface, the lacrimal system as well as tears. Furthermore, we examined the expression and.