Nonlinear Imaging to Characterize Mice Tissue from Experimental Schistosomiasis

Schistosomiasis is a neglected disease that however poses serious public health problems. The disease is caused by Schistosoma cercariae of contaminated water that penetrates the human skin. In the body, cercariae evolves to adult worms, which lay eggs. The liver is one of the organs seriously affected by the disease as it lodges Schistosoma eggs. The aim of this study is the analysis of fibrosis in liver tissues infected with Schistosoma mansoni. Mice hepatic tissues infected with Schistosoma mansoni is an experimental model that has been widely used to resemble the human disease [1]. We followed the evolution of the disease through three different stages: 30, 60, and 120 days post-infection – pre-patent, acute, and beginning of the chronic phases – in liver tissue cuts obtained from mice infected with schistosomiasis. The analysis was performed by multiphoton imaging through two-photon excitation fluorescence (2PEF) and second harmonic generation (SHG) microscopy. The 2PEF allowed to evaluate the cellular regions of the tissue and the SHG provided access to the collagen structural organization in the tissue. The presence of the Schistosoma eggs caused an increase of the collagen content and also changes in its structure. We show results that can clearly evaluate the diseases progress.

This work was supported by CNPq, CAPES, and FAPEMIG. The authors also acknowledge the René Rachou Institute – Oswaldo Cruz (Fiocruz), INCT of Carbon Nanomaterials, and INCT of Photonics (INFo).