RESUMEN
Patients with tear dysfunction often experience increased irritation symptoms when subjected to drafty and/or low humidity environmental conditions. The purpose of this study was to investigate the effects of low humidity stress (LHS) on corneal barrier function and expression of cornified envelope (CE) precursor proteins in the epithelium of C57BL/6 and c-jun N-terminal kinase 2 (JNK2) knockout (KO) mice. LHS was induced in both strains by exposure to an air draft for 15 (LHS15D) or 30 days (LHS30D) at a relative humidity <30%RH. Nonstressed (NS) mice were used as controls. Oregon-green-dextran uptake was used to measure corneal barrier function. Levels of small proline-rich protein (SPRR)-2, involucrin, occludin, and MMP-9 were evaluated by immunofluorescent staining in cornea sections. Wholemount corneas immunostained for occludin were used to measure mean apical cell area. Gelatinase activity was evaluated by in situ zymography. Expression of MMP, CE and inflammatory cytokine genes was evaluated by qPCR. C57BL/6 mice exposed to LHS15D showed corneal barrier dysfunction, decreased apical corneal epithelial cell area, higher MMP-9 expression and gelatinase activity and increased involucrin and SPRR-2 immunoreactivity in the corneal epithelium compared to NS mice. JNK2KO mice were resistant to LHS-induced corneal barrier disruption. MMP-3,-9,-13, IL-1α, IL-1ß, involucrin and SPRR-2a RNA transcripts were significantly increased in C57BL/6 mice at LHS15D, while no change was noted in JNK2KO mice. LHS is capable of altering corneal barrier function, promoting pathologic alteration of the TJ complex and stimulating production of CE proteins by the corneal epithelium. Activation of the JNK2 signaling pathway contributes to corneal epithelial barrier disruption in LHS.
Asunto(s)
Síndromes de Ojo Seco/enzimología , Epitelio Corneal/enzimología , Proteína Quinasa 9 Activada por Mitógenos/metabolismo , Estrés Fisiológico , Animales , Transporte Biológico , Proteínas Ricas en Prolina del Estrato Córneo/genética , Proteínas Ricas en Prolina del Estrato Córneo/metabolismo , Desecación , Síndromes de Ojo Seco/patología , Epitelio Corneal/patología , Técnica del Anticuerpo Fluorescente Indirecta , Humedad , Aparato Lagrimal/fisiología , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína Quinasa 9 Activada por Mitógenos/genética , Ocludina , Compuestos Orgánicos/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Two cases of GVHD with severe dry eyes are reported where conventional therapy failed to control ocular signs and symptoms. Autologous serum tears, however, resulted in a beneficial clinical effect with marked attenuation of the symptoms. This therapy proved to be safe during 10 months of treatment. Bone Marrow Transplantation (2000).