Do Complement Molecules Play a Role in Lens Regeneration?

Abstract

Abstract: : Purpose: Our studies aim to dissect the potential involvement of complement components during lens regeneration in the adult newt. We selected this urodele model because of its ability to regenerate its lens as an adult. Complement components are a family of molecules that play a crucial role in innate immunity. However, recent studies have suggested that complement components may play diverse and rather unconventional roles in several developmental and regenerative processes by modulating cell differentiation and promoting cell-cell interactions. It has been previously shown that C3 is expressed in the regenerating blastema of the amputated limb in urodeles, thus implicating complement as a critical mediator in regenerative pathways involving transdifferentiation and pattern formation (Del Rio-Tsonis et al., J. Immunol., 1998). These studies have now been extended to the lens regeneration model in urodeles and aim to elucidate the role of C3 and C5 complement molecules in this process. Methods: In situ hybrization and Immunohistochemistry using specific antibodies against C3 and C5 were used as tools to study the expression pattern of these molecules during lens regeneration. In addition, we used Cobra Venom Factor (CVF) to interfere with the complement pathway in vivo and examine its effects on lens regeneration. Results: Expression studies suggest that both C3 and C5 mRNA are produced by the cells of the dorsal iris that transdifferentiate to form the new lens. The protein expression data also shows that C3 and C5 are expressed in the eye during lens regeneration. Studies to assess the possible "in vivo" role of complement in regeneration are underway and will be discussed. Conclusions: Our results indicate that Complement components C3 and C5 are expressed during lens regeneration and that they might be implicated in the regulation of this process.

Keywords: regeneration • iris • immunohistochemistry