Schistosomiasis: proline production and release by ova

Area of Science:

• Biochemistry
• Parasitology
• Molecular Biology

Background:

• Schistosomiasis is a parasitic disease caused by Schistosoma mansoni.
• Granuloma formation and fibrosis are key pathological features of schistosomiasis.
• The role of proline in the pathogenesis of schistosomiasis is not fully understood.

Purpose of the Study:

• To quantify proline production and release by Schistosoma mansoni ova.
• To investigate the activity of key proline synthetic enzymes in Schistosoma mansoni ova.
• To explore the potential role of ova-derived proline in stimulating fibrosis.

Main Methods:

• Proline production and release were measured in cleaned Schistosoma mansoni ova.
• Enzyme activities of ornithine-delta-transaminase and delta 1-pyrroline-5-carboxylic acid reductase were assayed.
• Enzyme activities were compared between ova, adult schistosomes, and rat liver.

Main Results:

• Schistosoma mansoni ova release proline at a high rate (approx. 76 mumoles/100 cc/hr).
• Ova exhibit significantly higher activity of proline synthetic enzymes (ornithine-delta-transaminase and delta 1-pyrroline-5-carboxylic acid reductase) compared to adult schistosomes and rat liver.
• Ornithine-delta-transaminase activity in ova was twice that of adult schistosomes and seven times that of rat liver.
• delta 1-pyrroline-5-carboxylic acid reductase activity in ova was higher than in adult schistosomes and 35 times that of rat liver.

Conclusions:

• Schistosoma mansoni ova are a major source of proline.
• The high activity of proline synthetic enzymes in ova suggests a dedicated pathway for proline production.
• Ova-derived proline may stimulate fibrosis in schistosomiasis-associated granulomata.