Experimental model of allergic conjunctivitis: effect of pharmacological treatment with anti-inflammatory protein galectin-1

• Grant number: 11/21845-3
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2012
• End date: February 28, 2014
• Field of knowledge: Biological Sciences - Morphology - Histology
• Principal Investigator: Cristiane Damas Gil
• Grantee: Cristiane Damas Gil
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated researchers: Sonia Maria Oliani

Abstract

Allergic conjunctivitis (AC) is an immune complex disease involving mast cell degranulation in the conjunctiva and the release of inflammatory mediators and cytokines that cause the infiltration of inflammatory cells in this tissue. This inflammation is the main contributing factor for many ocular disorders and may lead to decreased visual acuity and even blindness. Generally, in the treatment of intraocular inflammation, glucocorticoids are administered and their side effects stimulate search for new therapeutic strategies. Among the anti-inflammatory mediators highlights the endogenous protein galectin-1 (Gal-1) capable of controlling the processo f transmigration of leukocytes, cytokine release and degranulation of mast cells, contributing to the homeostasis of the inflammatory reaction. However, the expression of Gal-1 in normal and inflamed ocular tissues has been little studied. Using an experimental model of AC, we will study the expression and mechanism of action of endogenous Gal-1 in ocular tissues of mice. Animals will be immunized (days 0 and 7) i.p. with ovalbumin (OVA; 1 µg) and on days 15 and 18, they will receive direct instillation into the conjunctival sac of OVA (250 µg) in 10 µl of PBS. Another group of sensitized animals will be pretreated i.p. in days 15-18 with Gal-1 recombinant protein (rGal-1; 0.3 µg per animal) or dexamethasone (0.5 mg/kg), diluted in 0.1 mL of PBS. Control group will receive only PBS. After 4 and 24 hours of last challenge with OVA, animals will be anesthetized, underwent cardiac puncture to collect blood and the tear fluid and, subsequently, killed by cervical dislocation for enucleation of the eyes and the dissection of spleen and lymph nodes. The studies will be conducted through: histopathological and quantitative analysis of mast cell and leukocytes in ocular tissues and blood, ultrastructural immunocytochemistry to detect the colocalization of Gal-1 and adhesion molecules L-selectin and b2-integrin in inflammatory cells in ocular tissues; Western blotting to detect the endogenous expression of Gal-1 and kinases from MAPK cascade in ocular tissues, spleen and lymph nodes and; levels of cytokines IL-2, IL-4, IL-5, IL-10 and IFN-³ in the blood, tear fluid and homogenates of ocular tissues, spleen and lymph nodes. The results may indicate the mechanism of action of Gal-1 in ocular allergic inflammatory processes and provide new therapeutic options. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MELLO, CLAUDIA BOSNIC; RAMOS, LISANDRA; GIMENES, ALEXANDRE DANTAS; DE MORAES ANDRADE, TERESA RAQUEL; OLIANI, SONIA MARIA; GIL, CRISTIANE DAMAS. Immunomodulatory Effects of Galectin-1 on an IgE-Mediated Allergic Conjunctivitis Model. INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE, v. 56, n. 2, p. 693-704, FEB 2015. (11/21845-3)

ZANON, CAROLINE DE FREITAS; SONEHARA, NATHALIA MARTINS; GIROL, ANA PAULA; GIL, CRISTIANE DAMAS; OLIANI, SONIA MARIA. Protective effects of the galectin-1 protein on in vivo and in vitro models of ocular inflammation. MOLECULAR VISION, v. 21, p. 1036-1050, SEP 2 2015. (11/21845-3, 11/05248-5, 12/02759-1)