Background The parasite Taenia solium causes neurocysticercosis (NCC) in humans and is a common cause of adult-onset epilepsy in the developing world. Hippocampal atrophy, which occurs far from the cyst, is an emerging new complication of NCC. Evaluation of molecular pathways in brain regions close to and distant from the cyst could offer insight into this pathology. Methods Rats were inoculated intracranially with T. solium oncospheres. After 4 months, RNA was extracted from brain tissue samples in rats with NCC and uninfected controls, and cDNA was generated. Expression of 38 genes related to different molecular pathways involved in the inflammatory response and healing was assessed by RT-PCR array. Results Inflammatory cytokines IFN-γ, TNF-α, and IL-1, together with TGF-β and ARG-1, were overexpressed in tissue close to the parasite compared to non-infected tissue. Genes for IL-1A, CSF-1, FN-1, COL-3A1, and MMP-2 were overexpressed in contralateral tissue compared to non-infected tissue. Conclusions The viable cysticerci in the rat model for NCC is characterized by increased expression of genes associated with a proinflammatory response and fibrosis-related proteins, which may mediate the chronic state of infection. These pathways appear to influence regions far from the cyst, which may explain the emerging association between NCC and hippocampal atrophy.
Bibliographical noteFunding Information:
This work was supported by INNOVATE PERU grant number: N-135 PNICP-PIAP 2015, MRV; CIENCIACTIVA PERU grant number: 118-2015-FONDECYT, MR V, the National Institutes of Health grants number: 5D43 TW006581, RH G and, U19AI129909 (Peru-JHU TMRC Program), HH G. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© 2021 Carmen-Orozco et al.