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Proteinases secreted by Fasciola hepatica degrade extracellular matrix and basement membrane components

P Berasaín1, F Goñi, S McGonigle

  • 1Unidad de Biologia Parasitaria, Instituto de Higiene, Montevideo, Uruguay.

Insights

The parasitic fluke Fasciola hepatica secretes cysteine proteinases that degrade extracellular matrix components like collagen, fibronectin, and laminin. These enzymes likely aid the parasite

Area of Science:

  • Parasitology
  • Molecular Biology
  • Biochemistry

Background:

  • The invasive stages of Fasciola hepatica, a parasitic trematode, release proteinases.
  • Understanding these proteinases is crucial for comprehending parasite invasion mechanisms.

Purpose of the Study:

  • To investigate the interaction of Fasciola hepatica excretory/secretory (E/S) products and purified cysteine proteinases (CL1 and CL2) with extracellular matrix and basement membrane macromolecules.
  • To determine the specific collagen types and other matrix proteins degraded by these enzymes.

Main Methods:

  • Analysis of proteinase activity in F. hepatica E/S products.
  • Purification and characterization of cysteine proteinases CL1 and CL2.
  • Degradation assays using fibrillar collagens (types I and III), type IV collagen, elastin, fibronectin, and laminin.
  • Sequence analysis of fibronectin degradation products.

Main Results:

  • F. hepatica E/S products exhibited collagenolytic activity against types I, III, and IV collagen.
  • Purified CL1 and CL2 degraded acid-soluble type III and type IV collagen but not insoluble type I collagen.
  • Neither E/S products nor purified proteinases showed elastinolytic activity.
  • Fibronectin and laminin were degraded by E/S products and by CL1 and CL2, yielding complete biologically active domains.

Conclusions:

  • Fasciola hepatica cysteine proteinases (CL1 and CL2) can degrade key extracellular matrix components.
  • These proteinases likely play a significant role in the parasite's tissue invasion process.
  • The degradation of fibronectin and laminin suggests a mechanism for facilitating parasite migration through host tissues.

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