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Post-transplantation, T helper 1 (Th1)-mediated immune rejection is the predominant cause of graft failure. Th1 cell sensitization occurs through complex and context-dependent interaction among antigen-presenting cell subsets, particularly CD11b+ dendritic cells (DC2) and CD103+ dendritic cells (DC1). This interaction necessitates further investigation in context of transplant immunity. We use a well-established pre-clinical models of corneal transplantation and identified distinct roles of migratory CD103+ DC1 in influencing the outcomes of the grafted tissue. In recipients with uninflamed corneal beds, migratory CD103+DC1 demonstrate a tolerogenic phenotype that modulate the immunogenic capacity of CD11b+DC2 primarily mediated by IL-10, suppressing alloreactive CD4+Th1 cells via the PD-L1/PD-1 pathway, and enhancing Treg-mediated tolerance via αvß8 integrin-activated TGFß1, thus facilitating graft survival. Conversely, in recipients with inflamed and vascularized corneal beds, IFN-γ produced by CD4+Th1 cells induces migratory CD103+DC1 to adopt an immunostimulatory phenotype, characterized by the downregulation of regulatory markers including αvß8 integrin and IL-10 and the upregulation of IL-12 and costimulatory molecules CD80/86, resulting in graft failure. The adoptive transfer of ex-vivo induced tolerogenic CD103+DC1(iDC1) effectively inhibits Th1 polarization and preserves the tolerogenic phenotype of their physiological counterparts. Collectively, our findings underscore the essential role played by CD103+DC1 in modulating host alloimmune responses.
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We explore the interaction between corneal immunity and mesenchymal stem/stromal cells (MSCs) and their potential in treating corneal and ocular surface disorders. We outline the cornea's immune privilege mechanisms and the immunomodulatory substances involved. In this realm, MSCs are characterized by their immunomodulatory properties and regenerative potential, making them promising for therapeutic application. Therefore, we focus on the role of MSCs in immune-mediated corneal diseases such as dry eye disease, corneal transplantation rejection, limbal stem cell deficiency, and ocular graft-versus-host disease. Preclinical and clinical studies demonstrate MSCs' efficacy in promoting corneal healing and reducing inflammation in these conditions. Overall, we emphasize the potential of MSCs as innovative therapies in ophthalmology, offering promising solutions for managing various ocular surface pathologies.
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Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis, and their dysfunction is implicated in the pathogenesis of various autoimmune disorders, including dry eye disease (DED). Treg dysfunction in DED allows T-helper cell 17 (Th17) mediated chronic inflammation at the ocular surface. In this study, the factors causing Treg dysfunction in DED were investigated. We observed reduced expression of Treg functional markers - FoxP3, CD25, and CTLA-4 in the cells isolated from DED mice (DED Tregs). Additionally, DED Tregs showed increased expression levels of receptors for pro-inflammatory cytokine receptors, namely IL-6R, IL-17RA, and IL-23R. An increased expression level of pro-inflammatory cytokine receptors was observed on exposing Tregs isolated from naïve mice (NTregs) to IL-6 or IL-17, but not IL-23, with a concomitant downregulation of FoxP3, CD25, and CTLA-4 in these cells. Furthermore, among these cytokines, IL-6 induced the most pronounced loss of Treg mediated suppression of Th17 proliferation and IL-10 secretion. In vitro and in vivo blockade of IL-6 effectively restored function in DED Tregs, leading to enhanced suppressive function against proliferating Th17 cells and ameliorating disease severity. In conclusion, this study provides insights into mechanisms of Treg dysregulation in DED, specifically delineating the effect of Th17-associated cytokines, with IL-6 emerging as the critical factor inducing Treg dysfunctionality. These findings highlight the potential for developing novel therapeutic interventions for DED through restoration of immunosuppressive function of Tregs.
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Modelos Animais de Doenças , Síndromes do Olho Seco , Fatores de Transcrição Forkhead , Interleucina-6 , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores , Animais , Linfócitos T Reguladores/imunologia , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/imunologia , Camundongos , Interleucina-6/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Células Th17/imunologia , Antígeno CTLA-4/metabolismo , Feminino , Citometria de Fluxo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Dessecação , Células CultivadasRESUMO
Purpose: To evaluate the therapeutic efficacy of topical application of a neurokinin-1 receptor (NK1R) antagonist in a rabbit model of nonallergic ocular redness. Methods: Nonallergic ocular redness was induced in rabbits by a single, topical application of dapiparzole hydrochloride eye drops (0.5%, 1%, 2%, or 5%). The NK1R antagonist L-703,606 was topically applied to the eye at the same time of induction or 20 min after induction, and phosphate buffered saline (PBS) treatment served as the control. Superior bulbar conjunctival images were taken every 30 s for the first 2 min, followed by every 4 min for 8 min, and then every 10 min until 1 h. The severity of ocular redness was evaluated on the images using ImageJ-based ocular redness index (ORI) calculations. Results: The ORI scores were significantly increased after the application of 0.5%, 1%, 2%, or 5% dapiparzole at each time point evaluated, with the most severe redness induced by the 5% dapiprazole that led to a maximal mean increase in ORI score of 14 at 20 min post-induction and thus used for subsequent evaluation of therapeutic efficacy of NK1R antagonism. Topical L-703,606, when applied at the same time as dapiprazole induction, significantly suppressed the increase of ORI scores at all time points (â¼40% decrease). Furthermore, when applied at 20 min after dapiprazole induction, L-703,606 rapidly and effectively suppressed the increase of ORI scores at 30, 40, 50, and 60 min (â¼30% decrease). Conclusions: Topical blockade of NK1R effectively prevents and alleviates nonallergic ocular redness in a novel animal model.
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Diabetes mellitus (DM) is one of the most prevalent diseases globally, and its prevalence is rapidly increasing. Most patients with a long-term history of DM present with some degree of keratopathy (DK). Despite its high incidence, the underlying inflammatory mechanism of DK has not been elucidated yet. For further insights into the underlying immunopathologic processes, we utilized streptozotocin-induced mice to model type 1 DM (T1D) and B6.Cg-Lepob/J mice to model type 2 DM (T2D). We evaluated the animals for the development of clinical manifestations of DK. Four weeks post-induction, the total frequencies of corneal CD45+CD11b+Ly-6G- myeloid cells, with enhanced gene and protein expression levels for the proinflammatory cytokines TNF-α and IL-1ß, were higher in both T1D and T2D animals. Additionally, the frequencies of myeloid cells/mm2 in the sub-basal neural plexus (SBNP) were significantly higher in T1D and T2D compared to non-diabetic mice. DK clinical manifestations were observed four weeks post-induction, including significantly lower tear production, corneal sensitivity, and epitheliopathy. Nerve density in the SBNP and intraepithelial terminal endings per 40x field were lower in both models compared to the normal controls. The findings of this study indicate that DM alters the immune quiescent state of the cornea during disease onset, which may be associated with the progressive development of the clinical manifestations of DK.
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Doenças da Córnea , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Humanos , Camundongos , Animais , Diabetes Mellitus Tipo 1/patologia , Córnea/patologia , Doenças da Córnea/patologia , Diabetes Mellitus Tipo 2/patologia , EstreptozocinaRESUMO
Myeloid derived suppressor cells (MDSCs) are a heterogenous population of immature hematopoietic precursors with known immunoregulatory functions. The immunosuppressive role of MDSCs has been highlighted in several inflammatory ophthalmic disorders; however, their therapeutic application in suppressing the immune-mediated changes in dry eye disease (DED) has not been studied. We observed significant reduction in antigen presenting cell (APC) frequencies and their maturation in the presence of MDSCs. Moreover, co-culturing MDSCs with T helper 17 cells (Th17) resulted in reduced Th17 frequencies and their IL-17 expression. On the contrary, MDSCs maintained regulatory T cell frequencies and enhanced their function in-vitro. Furthermore, we delineated the role of interleukin-10 (IL-10) secreted by MDSCs in their immunoregulatory functions. We confirmed these results by flow cytometry analysis and observed that treatment with MDSCs in DED mice effectively suppressed the maturation of APCs, pathogenic Th17 response, and maintained Treg function and significantly ameliorated the disease. The results in this study highlight the potential therapeutic application of MDSCs in treating refractory DED.
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Modelos Animais de Doenças , Síndromes do Olho Seco , Citometria de Fluxo , Camundongos Endogâmicos C57BL , Células Supressoras Mieloides , Linfócitos T Reguladores , Células Th17 , Animais , Células Supressoras Mieloides/imunologia , Síndromes do Olho Seco/imunologia , Síndromes do Olho Seco/metabolismo , Camundongos , Células Th17/imunologia , Linfócitos T Reguladores/imunologia , Células Apresentadoras de Antígenos/imunologia , Feminino , Progressão da Doença , Interleucina-10/metabolismo , Células Cultivadas , Técnicas de CoculturaRESUMO
Highly inflamed and neovascularized corneal graft beds are known as high-risk (HR) environments for transplant survival. One of the primary factors leading to this rejection is reduction in the suppressive function of regulatory T cells (Treg). Our results show that myeloid-derived suppressor cells (MDSC) counteract interleukin-6-mediated Treg dysfunction by expressing interleukin-10. Additionally, MDSC maintain forkhead box P3 stability and their ability to suppress IFN-γ+ Th1 cells. Administering MDSC to HR corneal transplant recipients demonstrates prolonged graft survival via promotion of Treg while concurrently suppressing IFN-γ+ Th1 cells. Moreover, MDSC-mediated donor-specific immune tolerance leads to long-term corneal graft survival as evidenced by the higher survival rate or delayed survival of a second-party C57BL/7 (B6) graft compared to those of third-party C3H grafts observed in contralateral low-risk or HR corneal transplantation of BALB/c recipient mice, respectively. Our study provides compelling preliminary evidence demonstrating the effectiveness of MDSC in preventing Treg dysfunction, significantly improving graft survival in HR corneal transplantation, and showing promising potential for immune tolerance induction.
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Purpose: To evaluate whether fibrosis contributes to corneal transplant failure and to determine whether effector CD4+ T cells, the key immune cells in corneal transplant rejection, play a direct role in fibrosis formation. Methods: Allogeneic corneal transplantation was performed in mice. Graft opacity was evaluated by slit-lamp biomicroscopy, and fibrosis was assessed by in vivo confocal microscopy. Expression of alpha-smooth muscle actin (α-SMA) in both accepted and failed grafts was assessed by real-time PCR and immunohistochemistry. Frequencies of graft-infiltrating CD4+ T cells, neutrophils, and macrophages were assessed using flow cytometry. In vitro, MK/T-1 corneal fibroblasts were co-cultured with activated CD4+CD25- effector T cells isolated from corneal transplant recipient mice, and α-SMA expression was quantified by real-time PCR and ELISA. Neutralizing antibody was used to evaluate the role of interferon gamma (IFN-γ) in promoting α-SMA expression. Results: The majority of failed grafts demonstrated clinical signs of fibrosis which became most evident at week 6 after corneal transplantation. Failed grafts showed higher expression of α-SMA as compared to accepted grafts. Flow cytometry analysis showed a significant increase in CD4+ T cells in failed grafts compared to accepted grafts. Co-culture of activated CD4+CD25- effector T cells with corneal fibroblasts led to an increase in α-SMA expression by fibroblasts. Inhibition of IFN-γ in culture significantly suppressed this increase in α-SMA expression as compared to immunoglobulin G control. Conclusions: Fibrosis contributes to graft opacity in corneal transplant failure and is mediated at least in part by effector CD4+ T cells via IFN-γ.
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Doenças da Córnea , Transplante de Córnea , Animais , Camundongos , Linfócitos T CD4-Positivos , Córnea , Anticorpos Neutralizantes , Interferon gamaRESUMO
Corneal endothelial cells (CEnCs) regulate corneal hydration and maintain tissue transparency through their barrier and pump function. However, these cells exhibit limited regenerative capacity following injury. Currently, corneal transplantation is the only established therapy for restoring endothelial function, and there are no pharmacologic interventions available for restoring endothelial function. This study investigated the efficacy of the neuropeptide α-melanocyte-stimulating hormone (α-MSH) in promoting endothelial regeneration during the critical window between ocular injury and the onset of endothelial decompensation using an established murine model of injury using transcorneal freezing. Local administration of α-MSH following injury prevented corneal edema and opacity, reduced leukocyte infiltration, and limited CEnC apoptosis while promoting their proliferation. These results suggest that α-MSH has a proregenerative and cytoprotective function on CEnCs and shows promise as a therapy for the prevention and management of corneal endothelial dysfunction.
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Córnea , Edema da Córnea , alfa-MSH , Feminino , Gravidez , Animais , Camundongos , Camundongos Endogâmicos BALB C , Humanos , Linhagem Celular , Córnea/citologia , Células Endoteliais , Edema da Córnea/tratamento farmacológico , Edema da Córnea/patologia , Preservação de Tecido , alfa-MSH/uso terapêutico , Citoproteção , Infiltração de Neutrófilos , Monócitos/metabolismo , Macrófagos/metabolismo , Cicatrização/efeitos dos fármacosRESUMO
Introducción: Las personas con cáncer necesitan recibir cuidados enfocados en aspectos biopsi-cosociales considerando la experiencia con la medicación (MedExp), la evolución de esta enfermedad y la calidad de vida relacionada con la salud (CRVS). Se presentan los resultados del Compre-hensive Medication Management (CMM) implanta-do en una institución colombiana especializada en oncología. Método: Diseño cuali-cuantitativo mixto observacional, descriptivo y prospectivo. Los datos se obtuvieron mediante triangulación de técnicas cualitativas (entrevistas en profundidad y observación participante) y cuantitativas (entrevistas clínicas con cuestionarios validados). Las entrevistas fueron presenciales y telemáticas por la pandemia (febrero-octubre 2021). Según los estándares del CMM, se generó la historia farmacoterapéutica, se registró la información biopsicosocial y se analizó la MedExp y la CVRS utilizando Medicines Optimisation Software®. Resultados: Se evaluaron los estándares antes y después de su implantación. La valoración inicial tuvo un análisis DAFO (Debilidades, Amenazas, Fortalezas, Oportunidades) consensuando estrategias para desarrollar CMM. El servicio de oncología derivó 17 personas, 10 mujeres aceptaron participar. Se completaron 30 entrevistas recogiendo narrativas sobre experiencias, observaciones y datos clínicos contextualizados a partir de las que se realizaron intervenciones biopsicosociales. Se resolvieron 2 condiciones clínicas, 2 mejoraron, 7 permanecieron estables, 9 mejoraron parcialmente y 4 no tuvieron mejoría. Tras recibir CMM, las participantes mejoraron su autopercepción en salud, y mejoraron principalmente las dimensiones de movilidad, realización de actividades cotidianas y ansiedad/depresión. Conclusiones: En la implantación del CMM se integró el modelo biopsicosocial considerando las experiencias reales de padecer cáncer alcanzando mejoría en condiciones clínicas y en CVRS de las pacientes atendidas. (AU)
Introduction: People with cancer need to receive care focused on biopsychosocial aspects, consid-ering medication experience (MedExp), disease and illness progression, and health-related quality of life (HRQoL). The results of the Comprehensive Medication Management (CMM) implemented in a Colombian institution specialized in oncology are presented. Method: Mixed observational, descriptive, and pro-spective qualitative-quantitative design. Data were obtained by triangulating qualitative (in-depth inter-views and participant observation) and quantitative techniques (clinical interviews with validated ques-tionnaires). Data was collected through interviews carried out face-to-face and remotely due to the pandemic situation during February-October 2021. According to CMM standards, the pharmacothera-peutic history was obtained, recorded, and MedExp and HRQoL were analyzed using Medicines Optimi-zation Software®. Results: The standards of pharmaceutical care practice were established through the implemen-tation of a SWOT analysis to support care process. The oncology service referred 17 people; 10 women agreed to participate. Thirty interviews were completed collecting narratives about experiences, observations and contextualized clinical data from which biopsychosocial interventions were carried out. Clinical results obtained were: 2 clinical condi-tions resolved, 2 improved, 7 stable, 9 partially im-proved and 4 unimprovement. After receiving CMM, the participants improved their self-perception of health, and HRQoL dimensions of mobility, daily activities, and anxiety/depression improved. Conclusions: Through the implementing of CMM, clinical conditions related to the patients medica-tions were improved. Results guided the actions to be followed when implementing this biopsychoso-cial model in the institution. Providing benefits for patients and caregivers, in terms of avoiding the deterioration of quality of life despite suffering from of oncological diseases.
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Psico-Oncologia/métodos , Assistência Farmacêutica , Serviço Hospitalar de Oncologia , Pacientes , Qualidade de Vida , Assistência Integral à Saúde , ColômbiaRESUMO
Corneal transplantation is the most common form of solid tissue grafting, with an approximately 80% to 90% success rate. However, success rates may decline when donor tissues are derived from patients with a history of diabetes mellitus (DM). To evaluate the underlying immunopathologic processes that cause graft rejection, we used streptozotocin-induced type 1 DM (DM1) and transgenic Lepob/ob type 2 DM (DM2) diabetic murine models as donors and nondiabetic BALB/c as recipients. DM resulted in an increased frequency of corneal antigen-presenting cells (APCs) with an acquired immunostimulatory phenotype. Following transplantation, recipients that received either type of diabetic graft showed increased APC migration and T helper type 1 alloreactive cells, impaired functional regulatory T cells, and graft survival. Insulin treatment in streptozotocin-induced diabetic mice led to an increased tolerogenic profile of graft APC, lower T helper type 1 sensitization, and a higher frequency of functional regulatory T cells with high suppressive capacity, reflected in increased graft survival. We conclude that both DM1 and DM2 in donors can impact corneal APC functional phenotype, rendering the tissue more immunogenic and thereby increasing the risk of graft failure.
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Transplante de Córnea , Diabetes Mellitus Experimental , Animais , Camundongos , Diabetes Mellitus Experimental/cirurgia , Diabetes Mellitus Experimental/patologia , Estreptozocina , Córnea , Células Apresentadoras de AntígenosRESUMO
PURPOSE: Descemet stripping only is an emerging surgical technique used to remove central Descemet membrane and corneal endothelial cells in patients with corneal endothelial disease. Here, we describe a murine model of this procedure to help facilitate basic science investigation and evaluation of postoperative outcomes using this surgical technique. METHODS: Slitlamp biomicroscopy, central corneal thickness assessment (by optical coherence tomography), and immunohistochemistry were used to assess the model through 7 weeks of follow-up. RESULTS: Complete removal of the endothelium and Descemet membrane was confirmed by slitlamp biomicroscopy and by histology. Central corneal thickness peaked at day 1 postinjury and then declined over the course of 2 weeks to a stable level of persistent edema. Seven weeks postinjury, immunohistochemical staining for ZO-1 showed the area of Descemet stripping was fully covered by enlarged and dysmorphic corneal endothelial cell. No significant ocular complications were appreciated through the end of the follow-up. CONCLUSIONS: We demonstrate the feasibility of and provide detailed instructions for a murine model of Descemet stripping only. This model provides a potential in vivo platform to investigate the mechanisms and biology of this emerging surgical procedure.
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Doenças da Córnea , Lesões da Córnea , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Animais , Camundongos , Endotélio Corneano/patologia , Modelos Animais de Doenças , Células Endoteliais , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Doenças da Córnea/cirurgia , Lesões da Córnea/cirurgia , Lâmina Limitante Posterior/cirurgiaRESUMO
Corneal transplant rejection primarily occurs because of the T helper 1 (Th1) effector cell-mediated immune response of the host towards allogeneic tissue. The evidence suggests that type 1 migratory conventional CD103+ dendritic cells (CD103+DC1) acquire an immunosuppressive phenotype in the tumor environment; however, the involvement of CD103+DC1 in allograft survival continues to be an elusive question of great clinical significance in tissue transplantation. In this study, we assess the role of CD103+DC1 in suppressing Th1 alloreactivity against transplanted corneal allografts. The immunosuppressive function of CD103+DC1 has been extensively studied in non-transplantation settings. We found that host CD103+DC1 infiltrates the corneal graft and migrates to the draining lymph nodes to suppress alloreactive CD4+ Th1 cells via the programmed death-ligand 1 axis. The systemic depletion of CD103+ DC1 in allograft recipients leads to amplified Th1 activation, impaired Treg function, and increased rate of allograft rejection. Although allograft recipient Rag1 null mice reconstituted with naïve CD4+CD25- T cells efficiently generated peripheral Treg cells (pTreg), the CD103+DC1-depleted mice failed to generate pTreg. Furthermore, adoptive transfer of pTreg failed to rescue allografts in CD103+DC1-depleted recipients from rejection. These data demonstrate the critical role of CD103+DC1 in regulating host alloimmune responses.
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PURPOSE: The purpose of this study was to establish a murine model of endothelial keratoplasty. METHODS: Endothelial keratoplasty (EK) was performed using C57BL/6 donor and BALB/c recipient mice. The central endothelium and Descemet membrane were removed from the recipient cornea, and a 1.5-mm posterior lamellar donor graft was made adherent to the recipient cornea with a small amount of viscoelastic. Mice were followed through slitlamp microscopy postoperatively, and OCT was used to assess the cornea and anterior chamber and measure central corneal thickness. Histology and immunohistochemistry were performed to confirm graft adherence and endothelial cell morphology. RESULTS: Successfully attached EK grafts were visualized in all transplanted animals. Histology and immunostaining confirmed proper graft orientation and adherence, as well as the presence of donor endothelium on transplanted grafts. We observed maximal corneal edema in all animals at day 1 postoperatively which gradually subsided. EK graft survival was 97% at 8 weeks. CONCLUSIONS: In this study, we describe a novel murine model for EK which we anticipate will enable detailed investigation into the cellular and molecular mechanisms involved in EK pathobiology.
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Transplante de Córnea , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Animais , Camundongos , Endotélio Corneano/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , CórneaRESUMO
BACKGROUND: Corneal transplantation outcomes are generally less favorable in young children compared with adults. The purpose of this study was to determine the immunological mechanisms underlying this difference. METHODS: A murine model of allogeneic corneal transplantation was used in the study, and graft survival was determined by evaluating opacity scores for 8 wk. Syngeneic transplantation in the very young host served as a surgical control. The frequencies of total and activated natural killer (NK) cells in cornea posttransplantation were kinetically evaluated using flow cytometry. The regulatory T cell (Treg) frequency and function in naive animals were assessed by flow cytometry and in vitro suppression assays, respectively. Finally, graft survival and immune responses were determined in NK cell-depleted, or adult naive Treg-transferred, young hosts. RESULTS: Corneal allograft survival in the very young recipients was significantly lower than in adult hosts. The frequencies of total NK cells and their interferon gamma-expressing subset in the cornea were significantly higher in the very young mice posttransplantation. In ungrafted mice, frequencies of Treg in draining lymph nodes as well as their capabilities to suppress NK-cell secretion of interferon gamma were lower in the very young compared with adults. In NK cell-depleted or adult Treg--transferred very young recipients, the allograft survival was significantly improved along with the suppressed NK-cell response. CONCLUSIONS: Our data demonstrate that amplified activity of NK cells, together with lower suppressive function of Treg, contributes to early rejection of corneal allografts in very young graft recipients.
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Transplante de Córnea , Linfócitos T Reguladores , Camundongos , Animais , Interferon gama , Córnea , Células Matadoras Naturais , Rejeição de Enxerto , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos BALB CRESUMO
PURPOSE: Allergic conjunctivitis is the most common cause leading to ocular redness (OR). Herein, using an animal model of allergic OR, we evaluated the therapeutic efficacy of topical blockade of substance P (SP) in treating red eye. METHODS: Allergic OR was induced in guinea pigs with topical histamine. Ocular SP was blocked using a specific SP receptor (neurokinin-1 receptor, NK1R) antagonist, L-703,606, via topical application 10 min before or 10 min after histamine instillation. Animal eyes were examined and a series of images were taken for up to 60 min post-OR induction. The severity of redness was analyzed using the quantitative ocular redness index (ORI). At the end of clinical examination, conjunctival tissues were collected for histological examination of conjunctival blood vessels and infiltrating eosinophils and neutrophils. In addition, SP concentration was quantified in the tear fluid and expression levels of inflammatory cytokines were assessed in the conjunctival tissues. RESULTS: Topical histamine application successfully induced red eye, evidenced by the significantly increased ORI during the observation period, with peak values at 10 min, along with significantly increased levels of SP in the tears. Topical treatment with L-703,606, either before histamine application or at the time of peak ORI, effectively reduced ORI and suppressed conjunctival blood vessel dilation, along with decreased eosinophil and neutrophil infiltration, and inflammatory cytokine expression in the conjunctiva, as well as reduced SP levels in the tears. CONCLUSIONS: Topical blockade of SP effectively prevents and treats allergy-related ocular redness by suppressing blood vessel dilation and allergic inflammation.
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Conjuntivite Alérgica , Substância P , Cobaias , Animais , Histamina/farmacologia , Histamina/uso terapêutico , Conjuntivite Alérgica/tratamento farmacológico , Conjuntivite Alérgica/etiologia , Túnica Conjuntiva/patologia , Eosinófilos/metabolismo , Eosinófilos/patologiaRESUMO
Corneal transplantation is the most common form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain tissue transparency by pumping out excess water from the cornea. After transplantation, the rate of CEnC loss far exceeds that seen with normal aging, which can threaten sight. The underlying mechanisms are poorly understood. Alpha-melanocyte-stimulating hormone (α-MSH) is a neuropeptide that is constitutively found in the aqueous humor with both cytoprotective and immunomodulatory effects. The curent study found high expression of melanocortin 1 receptor (MC1R), the receptor for α-MSH, on CEnCs. The effect of α-MSH/MC1R signaling on endothelial function and allograft survival in vitro and in vivo was investigated using MC1R signaling-deficient mice (Mc1re/e mice with a nonfunctional MC1R). Herein, the results indicate that in addition to its well-known immunomodulatory effect, α-MSH has cytoprotective effects on CEnCs after corneal transplantation, and the loss of MC1R signaling significantly decreases long-term graft survival in vivo. In conclusion, α-MSH/MC1R signaling is critical for CEnC function and graft survival after corneal transplantation.
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Córnea/imunologia , Transplante de Córnea , Células Endoteliais/imunologia , Sobrevivência de Enxerto/imunologia , Transdução de Sinais/imunologia , alfa-MSH/imunologia , Animais , Linhagem Celular Transformada , Córnea/patologia , Feminino , Sobrevivência de Enxerto/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Receptor Tipo 1 de Melanocortina/genética , Receptor Tipo 1 de Melanocortina/imunologia , Transdução de Sinais/genética , alfa-MSH/genéticaRESUMO
The translucent appearance of the conjunctiva allows for immediate visualization of changes in the circulation of the conjunctival microvasculature consisting of extensive branching of superficial and deep arterial systems and corresponding drainage pathways, and the translucent appearance of the conjunctiva allows for immediate visualization of changes in the circulation. Conjunctival hyperemia is caused by a pathological vasodilatory response of the microvasculature in response to inflammation due to a myriad of infectious and non-infectious etiologies. It is one of the most common contributors of ocular complaints that prompts visits to medical centers. Our understanding of these neurogenic and immune-mediated pathways has progressed over time and has played a critical role in developing targeted novel therapies. Due to a multitude of underlying etiologies, patients must be accurately diagnosed for efficacious management of conjunctival hyperemia. The diagnostic techniques used for the grading of conjunctival hyperemia have also evolved from descriptive and subjective grading scales to more reliable computer-based objective grading scales.
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Conjuntivite , Hiperemia , Túnica Conjuntiva , Humanos , Hiperemia/etiologia , InflamaçãoRESUMO
Conjunctival hyperemia is one of the most common causes for visits to primary care physicians, optometrists, ophthalmologists, and emergency rooms. Despite its high incidence, the treatment options for patients with conjunctival hyperemia are restricted to over-the-counter drugs that provide symptomatic relief due to short duration of action, tachyphylaxis and rebound redness. As our understanding of the immunopathological pathways causing conjunctival hyperemia expands, newer therapeutic targets are being discovered. These insights have also contributed to the development of animal models for mimicking the pathogenic changes in microvasculature causing hyperemia. Furthermore, this progress has catalyzed the development of novel therapeutics that provide efficacious, long-term relief from conjunctival hyperemia with minimal adverse effects.
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Conjuntivite , Hiperemia , Animais , Túnica Conjuntiva , Humanos , Soluções Oftálmicas , Fatores de TempoRESUMO
Pigment epithelium-derived factor (PEDF) is a widely expressed 50-kDa glycoprotein belonging to the serine protease inhibitor family, with well-established anti-inflammatory functions. Recently, we demonstrated the immunoregulatory role played by PEDF in dry eye disease (DED) by suppressing the maturation of antigen-presenting cells at the ocular surface following exposure to the desiccating stress. In this study, we evaluated the effect of PEDF on the immunosuppressive characteristics of regulatory T cells (Tregs), which are functionally impaired in DED. In the presence of PEDF, the in vitro cultures prevented proinflammatory cytokine (associated with type 17 helper T cells)-induced loss of frequency and suppressive phenotype of Tregs derived from normal mice. Similarly, PEDF maintained the in vitro frequency and enhanced the suppressive phenotype of Tregs derived from DED mice. On systemically treating DED mice with PEDF, moderately higher frequencies and significantly enhanced suppressive function of Tregs were observed in the draining lymphoid tissues, leading to the efficacious amelioration of the disease. Our results demonstrate that PEDF promotes the suppressive capability of Tregs and attenuates their type 17 helper T-cell-mediated dysfunction in DED, thereby playing a role in the suppression of DED.