The excretory/secretory products of fifth-stage larval Angiostrongylus cantonensis induces autophagy via the Sonic hedgehog pathway in mouse brain astrocytes

PLoS Negl Trop Dis. 2020 Jun 1;14(6):e0008290. doi: 10.1371/journal.pntd.0008290. eCollection 2020 Jun.

Abstract

Angiostrongyliasis is induced by the nematode Angiostrongylus cantonensis and leads to eosinophilic meningitis and meningoencephalitis in humans. Excretory-secretory products (ESPs) are important investigation targets for studying the relationship between hosts and nematodes. These products assist worms in penetrating the blood-brain barrier and avoiding the host immune response. Autophagy is a catabolic process that is responsible for digesting cytoplasmic organelles, proteins, and lipids and removing them through lysosomes. This process is essential to cell survival and homeostasis during nutritional deficiency, cell injury and stress. In this study, we investigated autophagy induction upon treatment with the ESPs of the fifth-stage larvae (L5) of A. cantonensis and observed the relationship between autophagy and the Shh pathway. First, the results showed that A. cantonensis infection induced blood-brain barrier dysfunction and pathological changes in the brain. Moreover, A. cantonensis L5 ESPs stimulated autophagosome formation and the expression of autophagy molecules, such as LC3B, Beclin, and p62. The data showed that upon ESPs treatment, rapamycin elevated cell viability through the activation of the autophagy mechanism in astrocytes. Finally, we found that ESPs induced the activation of the Sonic hedgehog (Shh) signaling pathway and that the expression of autophagy molecules was increased through the Shh signaling pathway. Collectively, these results suggest that A. cantonensis L5 ESPs stimulate autophagy through the Shh signaling pathway and that autophagy has a protective effect in astrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiostrongylus cantonensis / immunology
  • Angiostrongylus cantonensis / metabolism*
  • Animals
  • Astrocytes / cytology
  • Astrocytes / parasitology*
  • Autophagy*
  • Blood-Brain Barrier / physiopathology
  • Brain / parasitology
  • Brain / pathology*
  • Hedgehog Proteins / metabolism*
  • Host-Parasite Interactions
  • Larva / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction*
  • Snails

Substances

  • Hedgehog Proteins

Grants and funding

This work was supported in part by grants from the National Science Council, Executive Yuan, ROC (NSC105-2320-B-182-028-MY3 and 107-2320-B-039-070-MY2), the Chang Gung Memorial Hospital Research Grant (CMRPD1H0342 and CMRPD1H0442), and the China Medical University Research Grant (CMU108-S-45). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.