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Borna disease virus phosphoprotein impairs the developmental program controlling neurogenesis and reduces human GABAergic neurogenesis.

Scordel C, Huttin A, Cochet-Bernoin M, Szelechowski M, Poulet A, Richardson J, Benchoua A, Gonzalez-Dunia D, Eloit M, Coulpier M - PLoS Pathog. (2015)

Bottom Line: Using lentiviral vectors for expression of the bdv-p and bdv-x viral genes, we demonstrate that the phosphoprotein P, but not the X protein, diminishes human neurogenesis and, more particularly, GABAergic neurogenesis.We further reveal a decrease in pro-neuronal factors known to be involved in neuronal differentiation (ApoE, Noggin, TH and Scg10/Stathmin2), demonstrating that cellular dysfunction is associated with impairment of specific components of the molecular program that controls neurogenesis.Our findings thus provide the first evidence that a viral protein impairs GABAergic human neurogenesis, a process that is dysregulated in several neuropsychiatric disorders.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 1161, Maisons-Alfort, France; ANSES, UMR Virologie, Maisons-Alfort, France; Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, UMR Virologie, Maisons-Alfort, France.

ABSTRACT
It is well established that persistent viral infection may impair cellular function of specialized cells without overt damage. This concept, when applied to neurotropic viruses, may help to understand certain neurologic and neuropsychiatric diseases. Borna disease virus (BDV) is an excellent example of a persistent virus that targets the brain, impairs neural functions without cell lysis, and ultimately results in neurobehavioral disturbances. Recently, we have shown that BDV infects human neural progenitor cells (hNPCs) and impairs neurogenesis, revealing a new mechanism by which BDV may interfere with brain function. Here, we sought to identify the viral proteins and molecular pathways that are involved. Using lentiviral vectors for expression of the bdv-p and bdv-x viral genes, we demonstrate that the phosphoprotein P, but not the X protein, diminishes human neurogenesis and, more particularly, GABAergic neurogenesis. We further reveal a decrease in pro-neuronal factors known to be involved in neuronal differentiation (ApoE, Noggin, TH and Scg10/Stathmin2), demonstrating that cellular dysfunction is associated with impairment of specific components of the molecular program that controls neurogenesis. Our findings thus provide the first evidence that a viral protein impairs GABAergic human neurogenesis, a process that is dysregulated in several neuropsychiatric disorders. They improve our understanding of the mechanisms by which a persistent virus may interfere with brain development and function in the adult.

No MeSH data available.


Related in: MedlinePlus

bdv-p expression does not induce cellular death in differentiated hNPCs.Transduced hNPCs expressing bdv-p or bdv-x genes and their matched NT controls were induced to differentiate for 14 days and observed by (A) phase-contrast microscopy. Apoptosis was quantified based on (B) immunostaining with an antibody directed against cleaved-caspase 3 (green) and (C) TUNEL assay (green). Nuclei were stained with DAPI (blue). The data represent the mean of 2 independent experiments performed in triplicate. Statistical analyses were performed using the Mann-Whitney test. ns, non-significant (p > 0.5). Scale bar, 20 μm.
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ppat.1004859.g004: bdv-p expression does not induce cellular death in differentiated hNPCs.Transduced hNPCs expressing bdv-p or bdv-x genes and their matched NT controls were induced to differentiate for 14 days and observed by (A) phase-contrast microscopy. Apoptosis was quantified based on (B) immunostaining with an antibody directed against cleaved-caspase 3 (green) and (C) TUNEL assay (green). Nuclei were stained with DAPI (blue). The data represent the mean of 2 independent experiments performed in triplicate. Statistical analyses were performed using the Mann-Whitney test. ns, non-significant (p > 0.5). Scale bar, 20 μm.

Mentions: The decrease in the number of neurons in bdv-p-expressing hNPCs may have been due to increased death of cells committed to neuronal fate, or alternatively, to blockade in neuronal differentiation. To address the first possibility, we sought evidence of a cytopathic effect or apoptosis. Observation by phase-contrast microscopy at 4, 7, 10 and 14 days of differentiation did not reveal any obvious cytopathic effect in either bdv-p- or bdv-x-expressing hNPCs, as compared with their matched NT controls (Fig 4A, day 14). Apoptosis was sought in cells differentiated for 14 days by immunostaining using an antibody directed against cleaved caspase 3, a well-known apoptotic marker, and by TUNEL assay (Fig 4B and 4C). Observation and enumeration of cleaved-caspase-3- (Fig 4B) and TUNEL- (Fig 4C) positive cells revealed very few apoptotic cells in hNPCs, whether NT or expressing bdv-x or bdv-p. This showed that P did not compromise the survival of differentiating cells. Thus, P-induced reduction in the number of neurons appears to be due to the decreased capacity of hNPCs to differentiate into neurons rather than to impairment of their survival.


Borna disease virus phosphoprotein impairs the developmental program controlling neurogenesis and reduces human GABAergic neurogenesis.

Scordel C, Huttin A, Cochet-Bernoin M, Szelechowski M, Poulet A, Richardson J, Benchoua A, Gonzalez-Dunia D, Eloit M, Coulpier M - PLoS Pathog. (2015)

bdv-p expression does not induce cellular death in differentiated hNPCs.Transduced hNPCs expressing bdv-p or bdv-x genes and their matched NT controls were induced to differentiate for 14 days and observed by (A) phase-contrast microscopy. Apoptosis was quantified based on (B) immunostaining with an antibody directed against cleaved-caspase 3 (green) and (C) TUNEL assay (green). Nuclei were stained with DAPI (blue). The data represent the mean of 2 independent experiments performed in triplicate. Statistical analyses were performed using the Mann-Whitney test. ns, non-significant (p > 0.5). Scale bar, 20 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414417&req=5

ppat.1004859.g004: bdv-p expression does not induce cellular death in differentiated hNPCs.Transduced hNPCs expressing bdv-p or bdv-x genes and their matched NT controls were induced to differentiate for 14 days and observed by (A) phase-contrast microscopy. Apoptosis was quantified based on (B) immunostaining with an antibody directed against cleaved-caspase 3 (green) and (C) TUNEL assay (green). Nuclei were stained with DAPI (blue). The data represent the mean of 2 independent experiments performed in triplicate. Statistical analyses were performed using the Mann-Whitney test. ns, non-significant (p > 0.5). Scale bar, 20 μm.
Mentions: The decrease in the number of neurons in bdv-p-expressing hNPCs may have been due to increased death of cells committed to neuronal fate, or alternatively, to blockade in neuronal differentiation. To address the first possibility, we sought evidence of a cytopathic effect or apoptosis. Observation by phase-contrast microscopy at 4, 7, 10 and 14 days of differentiation did not reveal any obvious cytopathic effect in either bdv-p- or bdv-x-expressing hNPCs, as compared with their matched NT controls (Fig 4A, day 14). Apoptosis was sought in cells differentiated for 14 days by immunostaining using an antibody directed against cleaved caspase 3, a well-known apoptotic marker, and by TUNEL assay (Fig 4B and 4C). Observation and enumeration of cleaved-caspase-3- (Fig 4B) and TUNEL- (Fig 4C) positive cells revealed very few apoptotic cells in hNPCs, whether NT or expressing bdv-x or bdv-p. This showed that P did not compromise the survival of differentiating cells. Thus, P-induced reduction in the number of neurons appears to be due to the decreased capacity of hNPCs to differentiate into neurons rather than to impairment of their survival.

Bottom Line: Using lentiviral vectors for expression of the bdv-p and bdv-x viral genes, we demonstrate that the phosphoprotein P, but not the X protein, diminishes human neurogenesis and, more particularly, GABAergic neurogenesis.We further reveal a decrease in pro-neuronal factors known to be involved in neuronal differentiation (ApoE, Noggin, TH and Scg10/Stathmin2), demonstrating that cellular dysfunction is associated with impairment of specific components of the molecular program that controls neurogenesis.Our findings thus provide the first evidence that a viral protein impairs GABAergic human neurogenesis, a process that is dysregulated in several neuropsychiatric disorders.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR 1161, Maisons-Alfort, France; ANSES, UMR Virologie, Maisons-Alfort, France; Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, UMR Virologie, Maisons-Alfort, France.

ABSTRACT
It is well established that persistent viral infection may impair cellular function of specialized cells without overt damage. This concept, when applied to neurotropic viruses, may help to understand certain neurologic and neuropsychiatric diseases. Borna disease virus (BDV) is an excellent example of a persistent virus that targets the brain, impairs neural functions without cell lysis, and ultimately results in neurobehavioral disturbances. Recently, we have shown that BDV infects human neural progenitor cells (hNPCs) and impairs neurogenesis, revealing a new mechanism by which BDV may interfere with brain function. Here, we sought to identify the viral proteins and molecular pathways that are involved. Using lentiviral vectors for expression of the bdv-p and bdv-x viral genes, we demonstrate that the phosphoprotein P, but not the X protein, diminishes human neurogenesis and, more particularly, GABAergic neurogenesis. We further reveal a decrease in pro-neuronal factors known to be involved in neuronal differentiation (ApoE, Noggin, TH and Scg10/Stathmin2), demonstrating that cellular dysfunction is associated with impairment of specific components of the molecular program that controls neurogenesis. Our findings thus provide the first evidence that a viral protein impairs GABAergic human neurogenesis, a process that is dysregulated in several neuropsychiatric disorders. They improve our understanding of the mechanisms by which a persistent virus may interfere with brain development and function in the adult.

No MeSH data available.


Related in: MedlinePlus