Angiostrongylus costaricensis
is a nematode that causes abdominal angiostrongyliasis, a widespread human
parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages
of this helminth. First-stage larvae (L1) were obtained from the faeces of infected
Sigmodon hispidus
rodents and
third-stage larvae (L3) were collected from mollusks
Biomphalaria glabrata
previously infected with L1. Adult worms
were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles
followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and
found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating
the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely
determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in
solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic
proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and
L3 extracts. The characterization of protease expression throughout the
A. costaricensis life cycle may reveal key factors
influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.
