Limits...
Neuroinflammation induced by intracerebroventricular injection of microbial neuraminidase.

Granados-Durán P, López-Ávalos MD, Grondona JM, Gómez-Roldán Mdel C, Cifuentes M, Pérez-Martín M, Alvarez M, Rodríguez de Fonseca F, Fernández-Llebrez P - Front Med (Lausanne) (2015)

Bottom Line: The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes.Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans.Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Ciencias, Universidad de Málaga , Málaga , Spain.

ABSTRACT
In the present paper, we describe the facts that took place in the rat brain after a single injection of the enzyme neuraminidase from Clostridium perfringens into the right lateral ventricle. After injection, it diffused through the cerebrospinal fluid of the ipsilateral ventricle and the third ventricle, and about 400 μm into the periventricular brain parenchyma. The expression of ICAM1 in the endothelial cells of the periventricular vessels, IBA1 in microglia, and GFAP in astrocytes notably increased in the regions reached by the injected neuraminidase. The subependymal microglia and the ventricular macrophages begun to express IL1β and some appeared to cross the ependymal layer. After about 4 h of the injection, leukocytes migrated from large venules of the affected choroid plexus, the meninges and the local subependyma, and infiltrated the brain. The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes. Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans. Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content.

No MeSH data available.


Related in: MedlinePlus

(A) Panoramic view at the level of the foramen of Monro (fM) of the brain of an animal sacrificed 12 h after NA injection (red arrow points injection site). The tissue was immunostained with ICAM1. Note an increase in the immunoreactivity in the vessels of the affected periventricular zones (double-headed arrow) and the strong reactivity of the choroid plexus (cp) and the surface of the ependymal cells (arrow). The red squares correspond roughly to the zones used for quantification; some are detailed in (I,J). (B–D) Quantification of the expression of IBA1, GFAP, and ICAM1 in the periventricular area at selected times post-injection. Red squares in (A) point approximately the areas where micrographs were taken in the striatum and the septum. The values represented are the difference of stained area between the injected lateral ventricle (i) minus de contralateral ventricle (cl). The bars are the mean ± SEM of five animals analyzed. Letters (a–c) on bars indicate the absence (same letter) or presence (different letter) of a significant difference between groups (α = 0.05). (E,F) Immunoreactivity to IBA1 in the periventricular region at the level of the septum-fimbria (sf) in the injected (i) and the contralateral (cl) ventricles, 2 h after NA injection. (G,H) Details of GFAP staining in the stria medullaris (sm) in the injected (i) and the contralateral (cl) sides 12 h after the administration of NA. (I,J) Details [red squares in (A)] of the immunoreactivity to ICAM1 in the septum-fimbria (sf) subependymal parenchyma of the injected (i) and the contralateral (cl) sides 12 h after the injection of NA. Note the strong immunoreactivity of the ependymal surface in both ventriculi. (K,L) Twenty-four hours after NA injection, the optic chiasm (oc) beneath the third ventricle (IIIv) showed a higher IBA1 and GFAP staining in the injected (i) than in the contralateral side (cl). cl, contralateral ventricle; cp, choroid plexus; fM, foramen of Monro; i, injected lateralventricle; sfo, subfornical organ; sm, stria medularis; sf, septum-fimbria; oc, optic chiasm; IIIv, third ventricle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4362343&req=5

Figure 2: (A) Panoramic view at the level of the foramen of Monro (fM) of the brain of an animal sacrificed 12 h after NA injection (red arrow points injection site). The tissue was immunostained with ICAM1. Note an increase in the immunoreactivity in the vessels of the affected periventricular zones (double-headed arrow) and the strong reactivity of the choroid plexus (cp) and the surface of the ependymal cells (arrow). The red squares correspond roughly to the zones used for quantification; some are detailed in (I,J). (B–D) Quantification of the expression of IBA1, GFAP, and ICAM1 in the periventricular area at selected times post-injection. Red squares in (A) point approximately the areas where micrographs were taken in the striatum and the septum. The values represented are the difference of stained area between the injected lateral ventricle (i) minus de contralateral ventricle (cl). The bars are the mean ± SEM of five animals analyzed. Letters (a–c) on bars indicate the absence (same letter) or presence (different letter) of a significant difference between groups (α = 0.05). (E,F) Immunoreactivity to IBA1 in the periventricular region at the level of the septum-fimbria (sf) in the injected (i) and the contralateral (cl) ventricles, 2 h after NA injection. (G,H) Details of GFAP staining in the stria medullaris (sm) in the injected (i) and the contralateral (cl) sides 12 h after the administration of NA. (I,J) Details [red squares in (A)] of the immunoreactivity to ICAM1 in the septum-fimbria (sf) subependymal parenchyma of the injected (i) and the contralateral (cl) sides 12 h after the injection of NA. Note the strong immunoreactivity of the ependymal surface in both ventriculi. (K,L) Twenty-four hours after NA injection, the optic chiasm (oc) beneath the third ventricle (IIIv) showed a higher IBA1 and GFAP staining in the injected (i) than in the contralateral side (cl). cl, contralateral ventricle; cp, choroid plexus; fM, foramen of Monro; i, injected lateralventricle; sfo, subfornical organ; sm, stria medularis; sf, septum-fimbria; oc, optic chiasm; IIIv, third ventricle.

Mentions: A previous detailed study of immunostained serial sections allowed the selection of the levels to be studied. Thus, two sections from each animal (Bregma −0.3 and −0.92 mm approximately) were chosen for the quantification. In any case, the selected sections were close to the foramen of Monro but far enough from the site of injection as to avoid areas of surgically damaged tissue. In each section studied, micrographs were taken from the striatal ventricular wall, and from the septum-fimbria wall, both in the injected side and in the contralateral one (red squares in Figure 2A show the approximate location of the micrographs). Pictures were then processed using the image analysis software Visilog 6.3 (Noesis, France). To introduce a correction related to the basal level of expression of a particular marker in each animal, the immunostained area measured in the contralateral side was subtracted to the value obtained in the same location in the injected side. This correction was made to subtract the basal expression of a marker in each animal, which was found to vary from rat to rat. Afterwards, the mean value was obtained from the two locations and the two sections studied from each animal, which was considered the total stained area of that animal. A total of five animals were analyzed in each time post-injection studied.


Neuroinflammation induced by intracerebroventricular injection of microbial neuraminidase.

Granados-Durán P, López-Ávalos MD, Grondona JM, Gómez-Roldán Mdel C, Cifuentes M, Pérez-Martín M, Alvarez M, Rodríguez de Fonseca F, Fernández-Llebrez P - Front Med (Lausanne) (2015)

(A) Panoramic view at the level of the foramen of Monro (fM) of the brain of an animal sacrificed 12 h after NA injection (red arrow points injection site). The tissue was immunostained with ICAM1. Note an increase in the immunoreactivity in the vessels of the affected periventricular zones (double-headed arrow) and the strong reactivity of the choroid plexus (cp) and the surface of the ependymal cells (arrow). The red squares correspond roughly to the zones used for quantification; some are detailed in (I,J). (B–D) Quantification of the expression of IBA1, GFAP, and ICAM1 in the periventricular area at selected times post-injection. Red squares in (A) point approximately the areas where micrographs were taken in the striatum and the septum. The values represented are the difference of stained area between the injected lateral ventricle (i) minus de contralateral ventricle (cl). The bars are the mean ± SEM of five animals analyzed. Letters (a–c) on bars indicate the absence (same letter) or presence (different letter) of a significant difference between groups (α = 0.05). (E,F) Immunoreactivity to IBA1 in the periventricular region at the level of the septum-fimbria (sf) in the injected (i) and the contralateral (cl) ventricles, 2 h after NA injection. (G,H) Details of GFAP staining in the stria medullaris (sm) in the injected (i) and the contralateral (cl) sides 12 h after the administration of NA. (I,J) Details [red squares in (A)] of the immunoreactivity to ICAM1 in the septum-fimbria (sf) subependymal parenchyma of the injected (i) and the contralateral (cl) sides 12 h after the injection of NA. Note the strong immunoreactivity of the ependymal surface in both ventriculi. (K,L) Twenty-four hours after NA injection, the optic chiasm (oc) beneath the third ventricle (IIIv) showed a higher IBA1 and GFAP staining in the injected (i) than in the contralateral side (cl). cl, contralateral ventricle; cp, choroid plexus; fM, foramen of Monro; i, injected lateralventricle; sfo, subfornical organ; sm, stria medularis; sf, septum-fimbria; oc, optic chiasm; IIIv, third ventricle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4362343&req=5

Figure 2: (A) Panoramic view at the level of the foramen of Monro (fM) of the brain of an animal sacrificed 12 h after NA injection (red arrow points injection site). The tissue was immunostained with ICAM1. Note an increase in the immunoreactivity in the vessels of the affected periventricular zones (double-headed arrow) and the strong reactivity of the choroid plexus (cp) and the surface of the ependymal cells (arrow). The red squares correspond roughly to the zones used for quantification; some are detailed in (I,J). (B–D) Quantification of the expression of IBA1, GFAP, and ICAM1 in the periventricular area at selected times post-injection. Red squares in (A) point approximately the areas where micrographs were taken in the striatum and the septum. The values represented are the difference of stained area between the injected lateral ventricle (i) minus de contralateral ventricle (cl). The bars are the mean ± SEM of five animals analyzed. Letters (a–c) on bars indicate the absence (same letter) or presence (different letter) of a significant difference between groups (α = 0.05). (E,F) Immunoreactivity to IBA1 in the periventricular region at the level of the septum-fimbria (sf) in the injected (i) and the contralateral (cl) ventricles, 2 h after NA injection. (G,H) Details of GFAP staining in the stria medullaris (sm) in the injected (i) and the contralateral (cl) sides 12 h after the administration of NA. (I,J) Details [red squares in (A)] of the immunoreactivity to ICAM1 in the septum-fimbria (sf) subependymal parenchyma of the injected (i) and the contralateral (cl) sides 12 h after the injection of NA. Note the strong immunoreactivity of the ependymal surface in both ventriculi. (K,L) Twenty-four hours after NA injection, the optic chiasm (oc) beneath the third ventricle (IIIv) showed a higher IBA1 and GFAP staining in the injected (i) than in the contralateral side (cl). cl, contralateral ventricle; cp, choroid plexus; fM, foramen of Monro; i, injected lateralventricle; sfo, subfornical organ; sm, stria medularis; sf, septum-fimbria; oc, optic chiasm; IIIv, third ventricle.
Mentions: A previous detailed study of immunostained serial sections allowed the selection of the levels to be studied. Thus, two sections from each animal (Bregma −0.3 and −0.92 mm approximately) were chosen for the quantification. In any case, the selected sections were close to the foramen of Monro but far enough from the site of injection as to avoid areas of surgically damaged tissue. In each section studied, micrographs were taken from the striatal ventricular wall, and from the septum-fimbria wall, both in the injected side and in the contralateral one (red squares in Figure 2A show the approximate location of the micrographs). Pictures were then processed using the image analysis software Visilog 6.3 (Noesis, France). To introduce a correction related to the basal level of expression of a particular marker in each animal, the immunostained area measured in the contralateral side was subtracted to the value obtained in the same location in the injected side. This correction was made to subtract the basal expression of a marker in each animal, which was found to vary from rat to rat. Afterwards, the mean value was obtained from the two locations and the two sections studied from each animal, which was considered the total stained area of that animal. A total of five animals were analyzed in each time post-injection studied.

Bottom Line: The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes.Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans.Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Ciencias, Universidad de Málaga , Málaga , Spain.

ABSTRACT
In the present paper, we describe the facts that took place in the rat brain after a single injection of the enzyme neuraminidase from Clostridium perfringens into the right lateral ventricle. After injection, it diffused through the cerebrospinal fluid of the ipsilateral ventricle and the third ventricle, and about 400 μm into the periventricular brain parenchyma. The expression of ICAM1 in the endothelial cells of the periventricular vessels, IBA1 in microglia, and GFAP in astrocytes notably increased in the regions reached by the injected neuraminidase. The subependymal microglia and the ventricular macrophages begun to express IL1β and some appeared to cross the ependymal layer. After about 4 h of the injection, leukocytes migrated from large venules of the affected choroid plexus, the meninges and the local subependyma, and infiltrated the brain. The invading cells arrived orderly: first neutrophils, then macrophage-monocytes, and last CD8α-positive T-lymphocytes and B-lymphocytes. Leukocytes in the ventricles and the perivascular zones penetrated the brain parenchyma passing through the ependyma and the glia limitans. Thus, it is likely that a great part of the damage produced by microorganism invading the brain may be due to their neuraminidase content.

No MeSH data available.


Related in: MedlinePlus