| PurposeAutoimmune dry eye is more severe and refractory dry eye type. To date, the limited effective therapies are based on altering the symptom and decelerating the progression of dry eye. The low immunogenicity and immune suppression properties make MSCs as a promising therapeutic cell population. Autoimmune dacryoadenitis model is induced by injecting activated autologous PBL into rabbit ear marginal vein.This study will explore the immunomodulatory effects of Human Umbilical cord mesenchymal stem cells( h UC-MSCs)on autoimme dry eye and the potential immunomodulatory mechanisms.Methods1. The h UC-MSCs were obtained and tested the ability to differentiated into adipocyte and osteoblast lineages under distinct induction conditions.2. Induced rabbits autoimmune dry eye model: Autoimmune dacryoadenitis model is induced by injecting activated autologous PBL into rabbit ear marginal vein.3. The therapeutic treatment of stem cell started on the first day of disease induction,rabbits received 1×107 h UC-MSCs or PBS infusion on days 1, 2, 3, 4 and 5 after disease induction.4. Clinical assessment: All rabbits were examined before the study and every two weeks with slit-lamp biomicroscope for clinical signs. Tear production. tear stability and the cornea fluorescein staining were assessed.5. Lacrimal gland and conjunctiva were collected for histopholoty examination after 6weeks of each group.6. After 6 weeks, lymphocytes were isolated from the lacrimal gland and spleen, the proportion of Treg cells were measured by the flow cytometric analysis.7. After 6 weeks, lacrimal gland was harvested. Total RNA was isolated and reverse transcribed. Real- time PCR was used to analyze the m RNA expressions of cytokines and transcription factors.Results1. The h UC-MSCs were able to grown adhering to the wall with a shape of long fusiform or polygon, arranged in swirl and could be succeed in transdifferentiating into adipocytes and osteoblasts.2. The rabbit autoimmune dry eye model was also successfully induced: tear secretion was reduced?BUT was shorter and cornea obvious fluorescein staining.3. The h UC-MSCs have the therapeutic effects on induced autoimmune dry eye model.4. The rabbits of the h UC-MSCs treated group showed a significantly increased aqueous tear secrection, increased tear stability and cornea fluorescein staining was significantly reduce.5. Histopathology showed less lymphocytes infiltration of the lacrimal gland and conjunctiva compared with dry eye model group.6. The flow cytometric analysis revealed that Foxp3+ T cells were increased in the h UC-MSCs treated group in comparison with dry eye model group.7. Real-time PCR results revealed that the levels of inflammatory factors such as IL-6,IL-17,TNF-a,IFN-?,IL-1?,MMP-2/9,Foxp3,GATA-3m RNA from h UC-MSCs treated group were significantly decreased compared with dry eye model group.However, the levels of IL-10?TGF-??ROR?t and T-bet m RNA were increased.Conclusions1. Injection of the activated autologous PBL successfully induced Sj?gren's autoimmune dry eye. MMP-2/9may participate in the inflammatory response, leading to the occurrence of dry eye.2. HUC-MSCs transplantation alleviated the rabbit autoimmune dry eye and restored lacrimal gland secretory function,which by suppressing Th1/Th17 responses and favoring Tregs cells expansion, which may be related to the increased pro-inflammatory cytokines and decreased anti-inflammatory cytokines. Thus,reducing the tissue damage and the prevent progress of the disease. |
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