Lysophosphatidylcholine triggers cell differentiation in the protozoan parasite Herpetomonas samuelpessoai through the CK2 pathway.
BACKGROUND
Protozoa are distantly related to vertebrates but present some features of higher eukaryotes, making them good model systems for studying the evolution of basic processes such as the cell cycle. Herpetomonas samuelpessoai is a trypanosomatid parasite isolated from the hemipteran insect Zelus leucogrammus. Lysophosphatidylcholine (LPC) is implicated in the transmission and establishment of Chagas disease, whose etiological agent is Trypanosoma cruzi. LPC is synthesized by T. cruzi and its vectors, the hemipteran Rhodnius prolixus and Triatoma infestans. Platelet-activating factor (PAF), a phospholipid with potent and diverse physiological and pathophysiological actions, is a powerful inducer of cell differentiation in Herpetomonas muscarum muscarum and T. cruzi. The enzyme phospholipase A2 (PLA2) catalyzes the hydrolysis of the 2-ester bond of 3-sn-phosphoglyceride, transforming phosphatidylcholine (PC) into LPC.


METHODS
In this study, we evaluated cellular differentiation, PLA2 activity and protein kinase CK2 activity of H. samuelpessoai in the absence and in the presence of LPC and PAF.


RESULTS
We demonstrate that both PC and LPC promoted a twofold increase in the cellular differentiation of H. samuelpessoai, through CK2, with a concomitant inhibition of its cell growth. Intrinsic PLA2 most likely directs this process by converting PC into LPC.


CONCLUSIONS
Our results suggest that the actions of LPC on H. samuelpessoai occur upon binding to a putative PAF receptor and that the protein kinase CK2 plays a major role in this process. Cartoon depicting a model for the synthesis and functions of LPC in Herpetomonas samuelpessoai, based upon our results regarding the role of LPC on the cell biology of Trypanosoma cruzi [28-32]. N nucleus, k kinetoplast, PC phosphatidylcholine, LPC lysophosphatidylcholine, PLA2 phospholipase A2, PAFR putative PAF receptor in trypanosomatids [65], CK2 protein kinase CK2 [16].
['Dutra|Fernando L|FL|', 'Vieira|Danielle P|DP|http://orcid.org/0000-0002-8637-493X', 'Coelho|Felipe S|FS|', 'Adade|Camila M|CM|', 'Atella|Geórgia C|GC|', 'Silva Neto|Mário A C|MAC|', 'Lopes|Angela H|AH|']
D000818:Animals D047390:Casein Kinase II D002454:Cell Differentiation D004004:Dichlororibofuranosylbenzimidazole D004791:Enzyme Inhibitors D006430:Hemiptera D008244:Lysophosphatidylcholines D053858:Metabolic Networks and Pathways D054467:Phospholipases A2 D014230:Triazoles D014351:Trypanosomatina
Lysophosphatidylcholine Herpetomonas samuelpessoai Platelet-activating factor Phospholipase A2 Phosphatidylcholine Protein kinase CK2