Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.

<h4>Background</h4>Involvement of nitric oxide (NO) in the pathophysiology of human African trypanosomiasis (HAT) was analyzed in a HAT animal model (rat infected with Trypanosoma brucei brucei). With this model, it was previously reported that trypanosomes were capable of limiting trypa...

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Main Authors: Donia Amrouni, Anne Meiller, Sabine Gautier-Sauvigné, Monique Piraud, Bernard Bouteille, Philippe Vincendeau, Alain Buguet, Raymond Cespuglio
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-03-01
Series:PLoS ONE
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21408057/?tool=EBI
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author Donia Amrouni
Anne Meiller
Sabine Gautier-Sauvigné
Monique Piraud
Bernard Bouteille
Philippe Vincendeau
Alain Buguet
Raymond Cespuglio
author_facet Donia Amrouni
Anne Meiller
Sabine Gautier-Sauvigné
Monique Piraud
Bernard Bouteille
Philippe Vincendeau
Alain Buguet
Raymond Cespuglio
author_sort Donia Amrouni
collection DOAJ
description <h4>Background</h4>Involvement of nitric oxide (NO) in the pathophysiology of human African trypanosomiasis (HAT) was analyzed in a HAT animal model (rat infected with Trypanosoma brucei brucei). With this model, it was previously reported that trypanosomes were capable of limiting trypanocidal properties carried by NO by decreasing its blood concentration. It was also observed that brain NO concentration, contrary to blood, increases throughout the infection process. The present approach analyses the brain impairments occurring in the regulations exerted by arginase and N(G), N(G)-dimethylarginine dimethylaminohydrolase (DDAH) on NO Synthases (NOS). In this respect: (i) cerebral enzymatic activities, mRNA and protein expression of arginase and DDAH were determined; (ii) immunohistochemical distribution and morphometric parameters of cells expressing DDAH-1 and DDAH-2 isoforms were examined within the diencephalon; (iii) amino acid profiles relating to NOS/arginase/DDAH pathways were established.<h4>Methodology/principal findings</h4>Arginase and DDAH activities together with mRNA (RT-PCR) and protein (western-blot) expressions were determined in diencephalic brain structures of healthy or infected rats at various days post-infection (D5, D10, D16, D22). While arginase activity remained constant, that of DDAH increased at D10 (+65%) and D16 (+51%) in agreement with western-blot and amino acids data (liquid chromatography tandem-mass spectrometry). Only DDAH-2 isoform appeared to be up-regulated at the transcriptional level throughout the infection process. Immunohistochemical staining further revealed that DDAH-1 and DDAH-2 are contained within interneurons and neurons, respectively.<h4>Conclusion/significance</h4>In the brain of infected animals, the lack of change observed in arginase activity indicates that polyamine production is not enhanced. Increases in DDAH-2 isoform may contribute to the overproduction of NO. These changes are at variance with those reported in the periphery. As a whole, the above processes may ensure additive protection against trypanosome entry into the brain, i.e., maintenance of NO trypanocidal pressure and limitation of polyamine production, necessary for trypanosome growth.
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spelling doaj.art-c57249d01b96437a93e3a5faa28c25782022-12-21T21:27:20ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-03-0163e1689110.1371/journal.pone.0016891Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.Donia AmrouniAnne MeillerSabine Gautier-SauvignéMonique PiraudBernard BouteillePhilippe VincendeauAlain BuguetRaymond Cespuglio<h4>Background</h4>Involvement of nitric oxide (NO) in the pathophysiology of human African trypanosomiasis (HAT) was analyzed in a HAT animal model (rat infected with Trypanosoma brucei brucei). With this model, it was previously reported that trypanosomes were capable of limiting trypanocidal properties carried by NO by decreasing its blood concentration. It was also observed that brain NO concentration, contrary to blood, increases throughout the infection process. The present approach analyses the brain impairments occurring in the regulations exerted by arginase and N(G), N(G)-dimethylarginine dimethylaminohydrolase (DDAH) on NO Synthases (NOS). In this respect: (i) cerebral enzymatic activities, mRNA and protein expression of arginase and DDAH were determined; (ii) immunohistochemical distribution and morphometric parameters of cells expressing DDAH-1 and DDAH-2 isoforms were examined within the diencephalon; (iii) amino acid profiles relating to NOS/arginase/DDAH pathways were established.<h4>Methodology/principal findings</h4>Arginase and DDAH activities together with mRNA (RT-PCR) and protein (western-blot) expressions were determined in diencephalic brain structures of healthy or infected rats at various days post-infection (D5, D10, D16, D22). While arginase activity remained constant, that of DDAH increased at D10 (+65%) and D16 (+51%) in agreement with western-blot and amino acids data (liquid chromatography tandem-mass spectrometry). Only DDAH-2 isoform appeared to be up-regulated at the transcriptional level throughout the infection process. Immunohistochemical staining further revealed that DDAH-1 and DDAH-2 are contained within interneurons and neurons, respectively.<h4>Conclusion/significance</h4>In the brain of infected animals, the lack of change observed in arginase activity indicates that polyamine production is not enhanced. Increases in DDAH-2 isoform may contribute to the overproduction of NO. These changes are at variance with those reported in the periphery. As a whole, the above processes may ensure additive protection against trypanosome entry into the brain, i.e., maintenance of NO trypanocidal pressure and limitation of polyamine production, necessary for trypanosome growth.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21408057/?tool=EBI
spellingShingle Donia Amrouni
Anne Meiller
Sabine Gautier-Sauvigné
Monique Piraud
Bernard Bouteille
Philippe Vincendeau
Alain Buguet
Raymond Cespuglio
Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
PLoS ONE
title Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
title_full Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
title_fullStr Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
title_full_unstemmed Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
title_short Cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase (DDAH) in a rat model of sleeping sickness.
title_sort cerebral changes occurring in arginase and dimethylarginine dimethylaminohydrolase ddah in a rat model of sleeping sickness
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21408057/?tool=EBI
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