A. Barassi

B. Bonomelli

D. Taramelli

E. Galliera

G. Goi

L. Massaccesi

N. Basilico

N. Papini

S. Parapini

AIR Universita degli studi di Milano

S908
Microbiology - Infectious diseases
Cod: W099
ACTIVITY OF HUMAN ERYTHROCYTE MEMBRANE-BOUND GLYCOHYDROLASES IS RELATED TO
PLASMODIUM FALCIPARUM PRODUCTS
L. Massaccesi 1, N. Papini 4, S. Parapini 5, B. Bonomelli 1, D. Taramelli 5, A. Barassi 3, E. Galliera 2, G. Goi 1, N. Basilico 1
1Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy
2Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy; IRCCS Galeazzi Orthopaedic
institute, Milan, Italy
3Department of Health’s Science, Università degli Studi di Milano, Milan, Italy
4Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
5Department of Pharmacological and Biomolecular Sciences; Università degli Studi di Milano, Milan, Italy
(Italy)
luca.massaccesi@unimi.it
Background: Plasmodium falciparum (Pf) malaria causes about 600,000 deaths each year. Pathogenesis of anemia is
due to several factors including parasite induced hemolysis, diserythropoiesis and reduced deformability, accelerated
senescence and removal of uninfected red blood cells (RBC). Modifications of the physicochemical properties of RBC
plasma membranes and of their enzyme content can be ascribed to increased oxidative stress (OS) caused by parasite heme
products such as Fe(III)-protoporphyrin IX (hematin) or hemozoin, present at high concentration in the plasma of malaria
patients. Due to their role in signalling early membrane alterations in OS related pathologies, several plasma membrane
glycohydrolases of human RBC have been proposed as new markers of cellular OS. However, an association between RBC
glycohydrolases alteration and malaria infection has not been previously described.
The present work was aimed to investigate the ability of malaria parasite products to alter RBC membrane by affecting
glycohydrolases activity.
Methods: RBC from human donors were incubated for 24 hours in the presence of supernatants, derived from Pf cultures,
containing heme products released during parasite growth. RBC were then treated with different concentrations of hematin
(20-10-5 µg/ml) or hemozoin (10-5-2.5 µg/ml) purified from Pf cultures. Hexosaminidase, β-D-Glucuronidase, α-D-
Glucosidase and acidic Sialidase activities were evaluated by fluorimetric assays; membrane fluidity by fluorescence
anisotropy method.
Results: A decrease in the enzymatic activity was observed after incubation of RBC in the presence of culture supernatants
from different Pf strains. A significant dose dependent inhibition was observed after treatment with either hematin or
hemozoin. At the highest dose, hematin induced a decrease of enzymatic activity between 65% and 55%. Likewise a decrease
of RBC membrane fluidity was observed following treatment with hematin or hemozoin.
Conclusions: Our results are in agreement with accelerated RBC senescence observed in malaria infection and the parasite
heme products seems to be the main contributors to these membranes damages. Glycohydrolases alterations could be indeed
promising candidates as early markers of RBC damage in malaria infections.
Poster Abstracts – EuroMedLab Athens 2017 – Athens, 11-15 June 2017 • DOI 10.1515/cclm-2017-5026
Clin Chem Lab Med 2017; 55, Special Suppl, pp S1 – S1121, June 2017 • Copyright © by Walter de Gruyter • Berlin • Boston
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Activity of human erythrocyte membrane-bound glycohydrolases is related to Plasmodium Falciparum products

https://air.unimi.it/retrieve/handle/2434/502769/878432/MassaccesiEtAlii_cclm-2017-_Abstract.pdf

Activity of human erythrocyte membrane-bound glycohydrolases is related to Plasmodium Falciparum products

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