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Dry eye (DED) is a prevalent disease with immune-mediated inflammation as the principal pathophysiological etiology. Olive pomace, the major by-product of the olive oil industry, is rich in high-value polyphenols. Their anti-inflammatory and immunomodulatory activities were determined on human CD4+ T cells (hTCD4+) and in a DED animal model. The viability of hTCD4+ cells isolated from peripheral blood and activated with phytohemagglutinin-M was evaluated after treatment for 48 h with an olive pomace extract (OPT3, 0.10-0.40 mg/mL) and its major compound, hydroxytyrosol (25-100 mu M). Regarding the DED animal model, 100 mu M hydroxytyrosol, 0.20 mg/mL OPT3, or vehicle (borate buffer) were topically administered to 14 days-desiccating stress-exposed (constant airflow/scopolamine administration) C57BL/6 mice. Tear volume, corneal fluorescein staining (CFS), CD4+, and CD8+ T cell count in lymph nodes (flow cytometry), and IP-10 and TNF-alpha gene expression (qRT-PCR) in the cornea, conjunctiva, and lacrimal glands were evaluated. OPT3 (0.2-0.4 mg/mL) and hydroxytyrosol (100 mu M) significantly reduced hTCD4+ proliferation. In mice, both treatments reduced lacrimal gland IP-10 gene expression. OPT3 also decreased CFS, and conjunctival IP-10 and corneal TNF-alpha gene expression. In lymph nodes, hydroxytyrosol reduced CD3+, OPT3, and CD8+ count. Thus, a high-value application as a promising DED protection was proposed for olive pomace.

Purpose: Dry eye disease (DED) is a multifactorial disease, with limitations regarding efficacy and tolerability of applied substances. Among several candidates, the endocannabinoid system with its receptors (CB1R and CB2R) were reported to modulate inflammation, wound healing and pain, which are also core DED pathomechanisms. This study is to investigate the therapeutic responses of Delta-9 tetrahydrocannabinol (a non-selective agonist) and two selective antagonists, SR141716A (CB1R antagonist) and SR144528 (CB2R antagonist), as a topical application using a DED mouse model. Method: Experimental DED was induced in naive C57BL/6 mice. Expression of CBR at the ocular surface of naive and DED mice was determined by qPCR and in-situ hybridization. Either THC or CBR antagonists were compounded in an aqueous solution and dosed during the induction of DED. Tear production, cornea sensitivity, and cornea fluorescence staining were tested. At the end of each experiment, corneas were stained with beta 3-tubulin for analysis of corneal nerve morphology. Conjunctiva was analyzed for CD4(+) and CD8(+) infiltration. Results: CB1R and CB2R are present at the ocular surface, and desiccating stress increased CBR expressions (p < 0.05). After 10 days of DED induction, treated groups demonstrated a reduced CBR expression in the cornea, which was concurrent with improvements in the DED phenotype including fluorescence staining & inflammation. Applying THC protected corneal nerve morphology, thus maintained corneal sensitivity and reduced CD4(+) T-cell infiltration. The CB1R antagonist maintained cornea sensitivity without changing nerve morphology. Conclusions: Endocannabinoid receptor modulation presents a potential multi-functional therapeutic approach for DED.

Ocular graft-versus-host disease (oGVHD) is a fast progressing, autoimmunological disease following hematopoietic stem cell transplantation, leading to severe inflammation of the eye and destruction of the lacrimal functional unit with consecutive sight-threatening consequences. The therapeutic window of opportunity is narrow, and current treatment options are limited and often insufficient. To achieve new insights into the pathogenesis and to develop new therapeutic approaches, clinically relevant models of oGVHD are desirable. In this study, the ocular phenotype was described in a murine, chemotherapy-based, minor-mismatch GVHD model mimicking early-onset chronic oGVHD, with corneal epitheliopathy, inflammation of the lacrimal glands, and blepharitis. Additionally, corneal lymphangiogenesis was observed as part of oGVHD pathogenesis for the first time, thus opening up the investigation of lymphangiogenesis as a potential therapeutic and diagnostic tool.

Despite decades of experience with hematopoietic stem cell transplantation, we are still faced with the delicate equipoise of achieving stable ocular health post-transplantation. This is because ocular graft-versus-host disease (oGvHD) following hematopoietic stem cell transplantation frequently occurs (>= 50%) among transplant patients. To date, our understanding of the pathophysiology of oGvHD especially the involvement of the meibomian gland is still limited as a result of a lack of suitable preclinical models among other. Herein, the current state of the etiology and, pathophysiology of oGvHD based on existing pre-clinical models are reviewed. The need for additional pre-clinical models and knowledge about the involvement of the meibomian glands in oGvHD are emphasized.

Introduction: Anti-inflammatory, topical therapy of severe keratitis in dry eye disease (DED) and ocular graft-versus-host disease (oGvHD) includes steroids, cyclosporine (Cs), and others. In Germany, a commercial product containing 0.1% Cs in a cationic formulation is available since 2015. Objective: The aim of this study was to present real-life data using cationic 0.1% Cs in oGvHD patients. Methods: This was a retrospective study of 26 oGvHD and 41 DED patients with corneal staining of at least Oxford grade III. Parameters analyzed were Ocular Surface Disease Index, corneal staining, intraocular pressure, tear film break-up time, Schirmer, and visual acuity. In addition, it was evaluated how different Cs formulations were tolerated. Results: Corneal staining improved significantly in 1 eye in DED but not in oGvHD. In DED, cationic 0.1% Cs was not tolerated by 32% of the patients, in contrast to 0.05% Cs in castor oil not tolerated by 47% and liposomal 0.05% Cs by 63%. In oGvHD patients, cationic 0.1% Cs was not tolerated by 62%, 0.05% Cs in castor oil by 33%, and liposomal 0.05% Cs by 39% of the patients. Conclusions: This study demonstrates differences between the tolerance of different Cs formulations depending on the underlying cause of severe keratitis. Cationic 0.1% Cs is considerably less tolerated in oGvHD, and its use should be considered with care.