Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites

Nilay Nandi, Abhik Sen, Rajdeep Banerjee, Sudeep Kumar, Vikash Kumar, Amar Nath Ghosh, Pradeep Das

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Programmed cell death (PCD) is an essential process in the growth and development of multicellular organisms. However, accumulating evidence indicates that unicellular eukaryotes can also undergo PCD with apoptosis-like features. This study demonstrates that after exposure to 0.8 mM H2O2 for 9 h Entamoeba histolytica presents morphological and biochemical evidence of apoptosis-like death. Morphological characteristics of apoptosis-like death including DNA fragmentation, increased vacuolization, nuclear condensation and cell rounding were observed for H2O2-exposed trophozoites with preservation of membrane integrity. Biochemical alteration in ion fluxes is also a key feature in PCD, and H2O2-exposed trophozoites showed overproduction of reactive oxygen species, increased cytosolic Ca 2+ and decreased intracellular pH. Phosphatidylserine was also found to be expressed in the outer leaflet of the plasma membrane of the H 2O2-treated trophozoites. Pretreatment with the cysteine protease inhibitor E-64d, the extracellular and intracellular Ca2+ chelators EGTA and BAPTA/AM, and the Ca2+ influx inhibitor verapamil prior to H2O2 exposure abolished DNA fragmentation. The oxidatively stressed trophozoites also showed an increased calpain activity, indicating involvement of Ca2+-dependent calpain-like cysteine proteases in PCD of E. histolytica. A homogeneous caspase assay showed no significant caspase activity, and administration of caspase 1 inhibitor also did not prevent the death phenotype for the oxidatively stressed trophozoites, indicating a caspase-independent apoptosis-like death. Our observations clearly demonstrate that there is a distinct calpain-dependent but caspase-independent pathway for apoptosis-like death in oxidatively stressed E. histolytica trophozoites.

Original languageEnglish (US)
Pages (from-to)1926-1941
Number of pages16
JournalMicrobiology
Volume156
Issue number7
DOIs
StatePublished - Jul 1 2010

Fingerprint

Trophozoites
Entamoeba histolytica
Hydrogen Peroxide
Apoptosis
Caspases
Calpain
Cell Death
DNA Fragmentation
Cysteine Proteinase Inhibitors
Cysteine Proteases
Phosphatidylserines
Chelating Agents
Verapamil
Eukaryota
Growth and Development
Reactive Oxygen Species
Cell Membrane
Ions
Phenotype
Membranes

ASJC Scopus subject areas

  • Microbiology

Cite this

Nandi, N., Sen, A., Banerjee, R., Kumar, S., Kumar, V., Ghosh, A. N., & Das, P. (2010). Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites. Microbiology, 156(7), 1926-1941. https://doi.org/10.1099/mic.0.034066-0

Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites. / Nandi, Nilay; Sen, Abhik; Banerjee, Rajdeep; Kumar, Sudeep; Kumar, Vikash; Ghosh, Amar Nath; Das, Pradeep.

In: Microbiology, Vol. 156, No. 7, 01.07.2010, p. 1926-1941.

Research output: Contribution to journalArticle

Nandi, N, Sen, A, Banerjee, R, Kumar, S, Kumar, V, Ghosh, AN & Das, P 2010, 'Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites', Microbiology, vol. 156, no. 7, pp. 1926-1941. https://doi.org/10.1099/mic.0.034066-0
Nandi, Nilay ; Sen, Abhik ; Banerjee, Rajdeep ; Kumar, Sudeep ; Kumar, Vikash ; Ghosh, Amar Nath ; Das, Pradeep. / Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites. In: Microbiology. 2010 ; Vol. 156, No. 7. pp. 1926-1941.
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