Researchers have proposed that estrogen deficiency will lead to a Sjögren's syndrome (SjS)-like lacrimal gland inflammation, aqueous tear deficiency and dry eye. The purpose of this study was to determine whether this proposal is correct. Lacrimal glands were obtained from adult, age-matched wild type (WT) and aromatase knockout (ArKO) mice, in which estrogen synthesis is completely eliminated. Tissues were also obtained from autoimmune MRL/Mp-lpr/lpr (MRL/lpr) mice as inflammation controls. Tear volumes in WT and ArKO mice were measured and glands were processed for molecular biological and histological evaluation. Our results demonstrate that estrogen absence does not lead to a SjS-like inflammation in lacrimal tissue or to an aqueous-deficient dry eye. There was no upregulation of genes associated with inflammatory pathways in lacrimal glands of male or female ArKO mice. Such inflammatory activity was prominent in autoimmune MRL/lpr tissues. We also found no evidence of inflammation in lacrimal gland tissue sections of estrogen-deficient mice, and tear volumes of ArKO males were actually increased as compared to those WT controls. Interestingly, our study did show that estrogen absence influences the expression of thousands of lacrimal gland genes, and that this impact is sex- and genotype-specific. Our findings demonstrate that estrogen absence is not a risk factor for the development of SjS-like lacrimal gland inflammation or for aqueous-deficient dry eye in mice.
Purpose: To investigate bilateral tear cytokine levels in patients with unilateral bacterial keratitis (BK) as associated with in vivo confocal microscopic (IVCM) alterations in corneal nerves and dendritiform immune cells (DCs). Methods: Fifty-four (13 BK, 13 contralateral, 28 healthy controls) tear samples were collected prospectively and analyzed by multiplex microbeads assay. IVCM of the central cornea was performed on the same day and assessed for corneal nerve and DC alterations Results: Interleukin (IL)-1β, IL-6, and IL-8 were significantly elevated only in affected eyes (66.6±26.8 ρg/ml, 7,174±2,430, 810±315, P=0.04, P<0.001 and P<0.001), compared to healthy controls (13.0±4.0 ρg/ml, 171.8±32.1, 56.5±33.8). CCL-2, IL-10 and IL-17a were elevated only in contralateral eyes (813±478 ρg/ml, 86.7±38.3, 3,350±881, P=0.02, P=0.01, P=0.04), compared to controls (73.7±25.3 ρg/ml, 17.5 ±4.9, 1,350±337). Triggering receptor expressed on myeloid cells (TREM)-1 was significantly elevated in both affected (551±231 ρg/ml, P=0.02) and contralateral unaffected eyes (545±298 ρg/ml, P=0.03), compared to controls (31.3±12.4 ρg/ml). The density of DCs was significantly increased in both affected (226.9±37.3 cells/mm2, P<0.001) and unaffected eyes (122.3±23.7 cells/mm2, P<0.001) compared to controls (22.7±5.9 cells/mm2). Subbasal nerve density significantly decreased in affected eyes (3,337±1,615 μm/mm2, P<0.001) and contralateral eyes (13,230±1,635 μm/mm2, P<0.001) compared to controls (21,200±545 μm/mm2). IL-1β, IL-6 and IL-8 were significantly correlated with DC density (R=0.40, R=0.55 and R=0.31, all P<0.02) and nerve density (R=-0.30, R=-0.53 and R=-0.39, all P<0.01). Conclusions: Pro-inflammatory tear cytokines are elevated bilaterally in patients with unilateral BK, and are correlated strongly with alterations in DCs and nerve density as detected by IVCM.
There is currently considerable controversy about existence and classification of "lymphatic vessels" in the eye. Some of the confusion is certainly caused by inappropriate use (or nonuse) of the correct immunohistochemical markers. Many experts in the field expressed the need for a consensus statement, and, in this perspective, authors offer arguments and solutions to reliably continue with immunohistochemical ocular lymphatic research.
Purpose: To investigate whether systemically-injected syngeneic mesenchymal stem cells (MSCs) can home to the inflamed transplanted cornea, suppress induction of alloimmunity, and promote allograft survival. Methods: MSCs were generated from bone marrow of wild-type BALB/c or GFP+ C57BL/6 mice, and 1x106 cells were intravenously injected to allografted recipients 3 hours after surgery. MSCs homing to the cornea were examined at day 3 post-transplantation by immunohistochemistry. CD11c+MHC II+ cells were detected in the cornea and lymph nodes (LNs) 14 days post-transplantation using flow cytometry. Cytokine expression of bone marrow-derived dendritic cells (BMDCs) was determined using real-time PCR. ELISPOT assay was used to assess indirect and direct host T cell allosensitization, and graft survival was evaluated by slit-lamp biomicroscopy weekly up to 8 weeks. Results: Intravenously injected GFP+ MSCs were found in abundance in the transplanted cornea, conjunctiva, and lymph nodes, but not in the ungrafted (contralateral) tissue. The frequencies of mature CD11c+MHC II+ APCs were substantially decreased in the corneas and draining LNs of MSC-injected allograft recipients compared to control recipients. Maturation and function of in vitro cultured BMDCs was decreased when cocultured with MSCs. Draining LNs of MSC-injected allograft recipients showed significantly lower frequencies of IFNγ-secreting Th1 cells compared to the control group. Allograft survival rate was significantly higher in MSC-injected recipients compared to non-MSC injected recipients. Conclusions: Our data demonstrate that systemically-administered MSCs specifically home to transplanted corneas and promote allograft survival by inhibiting APC maturation and induction of alloreactive T cells.
PURPOSE: The aim of this study was to develop a modified ex vivo corneal cross-linking method that increases stromal resistance to enzymatic degradation for use as a carrier for the Boston keratoprosthesis. METHODS: Ex vivo cross-linking of human corneas was performed using Barron artificial anterior chambers. The corneas were deepithelialized, pretreated with riboflavin solution (0.1% riboflavin/20% dextran), and irradiated with ultraviolet A (UV-A) light (λ = 370 nm, irradiance = 3 mW/cm) for various durations. The combined effect of UV-A and gamma (γ) irradiation was also assessed using the commercially available γ-irradiated corneal donors. The corneas were then trephined and incubated at 37°C with 0.3% collagenase A solution. The time to dissolution of each cornea was compared across treatments. RESULTS: Deepithelialized corneas (no UV light, no riboflavin) dissolved in 5.8 ± 0.6 hours. Cross-linked corneas demonstrated increased resistance to dissolution, with a time to dissolution of 17.8 ± 2.6 hours (P < 0.0001). The corneal tissues' resistance to collagenase increased with longer UV-A exposure, reaching a plateau at 30 minutes. Cross-linking both the anterior and posterior corneas did not provide added resistance when compared with cross-linking the anterior corneas only (P > 0.05). γ-irradiated corneas dissolved as readily as deepithelialized controls regardless of whether they were further cross-linked (5.6 ± 1.2 hours) or not (6.1 ± 0.6 hours) (P = 0.43). CONCLUSIONS: Collagen cross-linking of the deepithelialized anterior corneal surface for 30 minutes conferred optimal resistance to in vitro keratolysis by collagenase A.
PURPOSE: The aim of this study was to report the clinical, imaging, and histopathological findings of bilateral, conjunctival adult-onset xanthogranulomas that raised the prospect of a mild form of Erdheim-Chester disease. METHODS: This is a case report. RESULTS: A 35-year-old white male complaining of ocular irritation, presented with bilateral, nasal and temporal, yellow, elevated conjunctival lumps first noticed 1.5 years back, which were not associated with other ocular findings. The lesions were firm, attached to the underlying episclera, and measured 1.1 × 0.9, 1.1 × 0.8, 1.2 × 0.5, and 0.5 × 0.5 cm in the temporal and nasal right and left eyes, respectively. Each mass was fleshy with vascularity at the peripheral margin. Histopathologic evaluation after excisional biopsy revealed lipidized xanthoma cells, multiple Touton giant cells, and lymphocytes. Immunohistochemical staining was positive for adipophilin (lipid), CD68, CD163 histiocytes, CD3 T cells (with CD8 cytotoxic T cells > CD4 T-helper cells), and virtually no CD20 B cells or IgG4 plasma cells. The patient later acquired similar xanthogranulomatous subcutaneous lesions on the extremities. Positron emission tomography scans showed sclerosis in the medullary cavities of the tibia and the radius of both legs and arms, and an absence of retroperitoneal lesions. A normal serum immunoelectrophoresis and the absence of a BRAF gene mutation were demonstrated. CONCLUSIONS: Adult-onset xanthogranuloma can present as a solitary conjunctival mass without periocular or orbital involvement. The clinical, histopathologic, and radiologic findings in this case are suggestive of Erdheim-Chester disease without displaying any life-threatening lesions to date. Histopathologic and imaging studies can help in obtaining a diagnosis. Ophthalmologists should be aware that xanthogranulomatous conditions may have potential systemic implications, and a thorough systemic evaluation is recommended for lesions that initially seemed to be isolated in nature.