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White matter loss in a mouse model of periventricular leukomalacia is rescued by trophic factors.

Espinosa-Jeffrey A, Barajas SA, Arrazola AR, Taniguchi A, Zhao PM, Bokhoor P, Holley SM, Dejarme DP, Chu B, Cepeda C, Levine MS, Gressens P, Feria-Velasco A, de Vellis J - Brain Sci (2013)

Bottom Line: In PVL, glutamate excitotoxicity (GME) leads to abnormal oligodendrocytes (OLs), myelin deficiency, and ventriculomegaly.Here, we produced a periventricular white matter lesion with a single intracerebral injection of N-methyl-d-aspartate (NMDA).Comparing lesions produced by NMDA alone and those produced by NMDA + TSC1 we found that: NMDA affected survival and reduced migration of OL progenitors (OLPs).

View Article: PubMed Central - PubMed

Affiliation: Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry, University of California Los Angeles, Los Angeles, CA 90095, USA. aespinosa@mednet.ucla.edu.

ABSTRACT
Periventricular leukomalacia (PVL) is the most frequent cause of cerebral palsy and other intellectual disabilities, and currently there is no treatment. In PVL, glutamate excitotoxicity (GME) leads to abnormal oligodendrocytes (OLs), myelin deficiency, and ventriculomegaly. We have previously identified that the combination of transferrin and insulin growth factors (TSC1) promotes endogenous OL regeneration and remyelination in the postnatal and adult rodent brain. Here, we produced a periventricular white matter lesion with a single intracerebral injection of N-methyl-d-aspartate (NMDA). Comparing lesions produced by NMDA alone and those produced by NMDA + TSC1 we found that: NMDA affected survival and reduced migration of OL progenitors (OLPs). In contrast, mice injected with NMDA + TSC1 proliferated twice as much indicating that TSC1 supported regeneration of the OLP population after the insult. Olig2-mRNA expression showed 52% OLP survival in mice receiving a NMDA injection and increased to 78% when TSC1 + NMDA were injected simultaneously and ventricular size was reduced by TSC1. Furthermore, in striatal slices TSC1 reduced the inward currents induced by NMDA in medium-sized spiny neurons, demonstrating neuroprotection. Thus, white matter loss after excitotoxicity can be partially rescued as TSC1 conferred neuroprotection to preexisting OLP and regeneration via OLP proliferation. Furthermore, we showed that early TSC1 administration maximizes neuroprotection.

No MeSH data available.


Related in: MedlinePlus

Acute NMDA exposure elicits the expression of HSP-90 in the CC and TSC1 neutralizes the NMDA effect. Coronal brain slices 300 μm thick were used for the acute treatment of NMDA alone or in slices pre-incubated with TSC1. After electrophysiology, slices were fixed and immunolabeled for the cell stress marker HSP-90 and the OL marker CNPase. (A–D) representative views of untreated slices, neither nestin (A) nor CNPase-expressing cells (C-arrowheads) were labeled for HSP-90 (B-circle). (D) merged image. After acute NMDA, CNPase-positive OL expressed HSP-90 (E–F). Moreover, cells that were not labeled for either of the two markers also expressed HSP-90 (F,G-thin arrows and circle). In slices pre-incubated with TSC1 followed by acute NMDA treatment (see methods for details) (I–L) the majority of CNPase-positive cells did not express HSP-90 (K). Nestin-positive cells did not express HSP-90 in the presence of TSC1 (I-circle). Some cells co-expressed CNPase and HSP-90 (J,K and L-open arrows). Insets show higher magnification views of the cells pointed by open arrows in (J) and (L). Arrowhead points to a CNPase-positive cell (K) that co-expresses HSP-90 (L). The inset in (J) shows an example on the colocalization of both HSP90 and CNPase both, in the cell body and processes (K,L). Calibration bar in (I) corresponds to 50 μm.
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brainsci-03-01461-f006: Acute NMDA exposure elicits the expression of HSP-90 in the CC and TSC1 neutralizes the NMDA effect. Coronal brain slices 300 μm thick were used for the acute treatment of NMDA alone or in slices pre-incubated with TSC1. After electrophysiology, slices were fixed and immunolabeled for the cell stress marker HSP-90 and the OL marker CNPase. (A–D) representative views of untreated slices, neither nestin (A) nor CNPase-expressing cells (C-arrowheads) were labeled for HSP-90 (B-circle). (D) merged image. After acute NMDA, CNPase-positive OL expressed HSP-90 (E–F). Moreover, cells that were not labeled for either of the two markers also expressed HSP-90 (F,G-thin arrows and circle). In slices pre-incubated with TSC1 followed by acute NMDA treatment (see methods for details) (I–L) the majority of CNPase-positive cells did not express HSP-90 (K). Nestin-positive cells did not express HSP-90 in the presence of TSC1 (I-circle). Some cells co-expressed CNPase and HSP-90 (J,K and L-open arrows). Insets show higher magnification views of the cells pointed by open arrows in (J) and (L). Arrowhead points to a CNPase-positive cell (K) that co-expresses HSP-90 (L). The inset in (J) shows an example on the colocalization of both HSP90 and CNPase both, in the cell body and processes (K,L). Calibration bar in (I) corresponds to 50 μm.

Mentions: Coronal slices were exposed to either NMDA alone or pre-incubated for 1 h to 2 h in TSC1 and subsequently exposed to NMDA. After electrophysiology as shown (Figure 5), slices were fixed and examined through double immunofluorescence for the cell stress marker heat shock protein 90 (HSP-90) and the OL marker cyclic nucleotide 3′-phosphohydrolase (CNPase). The results showed that HSP-90 was expressed in the CC white matter in NMDA-treated mice but not in non-treated slices (Figure 6A–D vs.Figure 6E–L respectively). Those slices that were pre-incubated with TSC1 presented a clear expression of HSP-90 at the level of the cell soma and processes but not along axonal fibers. CNPase expression was observed and not all CNPase positive cells expressed HSP-90. In contrast, slices treated with NMDA without pre-incubation in TSC1 showed a diffuse distribution of HSP-90 preferentially along the fibers expressed in mini-compartments like “puncta” and only few inter-fascicular cells were clearly seen expressing this stress protein but not CNPase (Figure 6F,G).


White matter loss in a mouse model of periventricular leukomalacia is rescued by trophic factors.

Espinosa-Jeffrey A, Barajas SA, Arrazola AR, Taniguchi A, Zhao PM, Bokhoor P, Holley SM, Dejarme DP, Chu B, Cepeda C, Levine MS, Gressens P, Feria-Velasco A, de Vellis J - Brain Sci (2013)

Acute NMDA exposure elicits the expression of HSP-90 in the CC and TSC1 neutralizes the NMDA effect. Coronal brain slices 300 μm thick were used for the acute treatment of NMDA alone or in slices pre-incubated with TSC1. After electrophysiology, slices were fixed and immunolabeled for the cell stress marker HSP-90 and the OL marker CNPase. (A–D) representative views of untreated slices, neither nestin (A) nor CNPase-expressing cells (C-arrowheads) were labeled for HSP-90 (B-circle). (D) merged image. After acute NMDA, CNPase-positive OL expressed HSP-90 (E–F). Moreover, cells that were not labeled for either of the two markers also expressed HSP-90 (F,G-thin arrows and circle). In slices pre-incubated with TSC1 followed by acute NMDA treatment (see methods for details) (I–L) the majority of CNPase-positive cells did not express HSP-90 (K). Nestin-positive cells did not express HSP-90 in the presence of TSC1 (I-circle). Some cells co-expressed CNPase and HSP-90 (J,K and L-open arrows). Insets show higher magnification views of the cells pointed by open arrows in (J) and (L). Arrowhead points to a CNPase-positive cell (K) that co-expresses HSP-90 (L). The inset in (J) shows an example on the colocalization of both HSP90 and CNPase both, in the cell body and processes (K,L). Calibration bar in (I) corresponds to 50 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061895&req=5

brainsci-03-01461-f006: Acute NMDA exposure elicits the expression of HSP-90 in the CC and TSC1 neutralizes the NMDA effect. Coronal brain slices 300 μm thick were used for the acute treatment of NMDA alone or in slices pre-incubated with TSC1. After electrophysiology, slices were fixed and immunolabeled for the cell stress marker HSP-90 and the OL marker CNPase. (A–D) representative views of untreated slices, neither nestin (A) nor CNPase-expressing cells (C-arrowheads) were labeled for HSP-90 (B-circle). (D) merged image. After acute NMDA, CNPase-positive OL expressed HSP-90 (E–F). Moreover, cells that were not labeled for either of the two markers also expressed HSP-90 (F,G-thin arrows and circle). In slices pre-incubated with TSC1 followed by acute NMDA treatment (see methods for details) (I–L) the majority of CNPase-positive cells did not express HSP-90 (K). Nestin-positive cells did not express HSP-90 in the presence of TSC1 (I-circle). Some cells co-expressed CNPase and HSP-90 (J,K and L-open arrows). Insets show higher magnification views of the cells pointed by open arrows in (J) and (L). Arrowhead points to a CNPase-positive cell (K) that co-expresses HSP-90 (L). The inset in (J) shows an example on the colocalization of both HSP90 and CNPase both, in the cell body and processes (K,L). Calibration bar in (I) corresponds to 50 μm.
Mentions: Coronal slices were exposed to either NMDA alone or pre-incubated for 1 h to 2 h in TSC1 and subsequently exposed to NMDA. After electrophysiology as shown (Figure 5), slices were fixed and examined through double immunofluorescence for the cell stress marker heat shock protein 90 (HSP-90) and the OL marker cyclic nucleotide 3′-phosphohydrolase (CNPase). The results showed that HSP-90 was expressed in the CC white matter in NMDA-treated mice but not in non-treated slices (Figure 6A–D vs.Figure 6E–L respectively). Those slices that were pre-incubated with TSC1 presented a clear expression of HSP-90 at the level of the cell soma and processes but not along axonal fibers. CNPase expression was observed and not all CNPase positive cells expressed HSP-90. In contrast, slices treated with NMDA without pre-incubation in TSC1 showed a diffuse distribution of HSP-90 preferentially along the fibers expressed in mini-compartments like “puncta” and only few inter-fascicular cells were clearly seen expressing this stress protein but not CNPase (Figure 6F,G).

Bottom Line: In PVL, glutamate excitotoxicity (GME) leads to abnormal oligodendrocytes (OLs), myelin deficiency, and ventriculomegaly.Here, we produced a periventricular white matter lesion with a single intracerebral injection of N-methyl-d-aspartate (NMDA).Comparing lesions produced by NMDA alone and those produced by NMDA + TSC1 we found that: NMDA affected survival and reduced migration of OL progenitors (OLPs).

View Article: PubMed Central - PubMed

Affiliation: Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry, University of California Los Angeles, Los Angeles, CA 90095, USA. aespinosa@mednet.ucla.edu.

ABSTRACT
Periventricular leukomalacia (PVL) is the most frequent cause of cerebral palsy and other intellectual disabilities, and currently there is no treatment. In PVL, glutamate excitotoxicity (GME) leads to abnormal oligodendrocytes (OLs), myelin deficiency, and ventriculomegaly. We have previously identified that the combination of transferrin and insulin growth factors (TSC1) promotes endogenous OL regeneration and remyelination in the postnatal and adult rodent brain. Here, we produced a periventricular white matter lesion with a single intracerebral injection of N-methyl-d-aspartate (NMDA). Comparing lesions produced by NMDA alone and those produced by NMDA + TSC1 we found that: NMDA affected survival and reduced migration of OL progenitors (OLPs). In contrast, mice injected with NMDA + TSC1 proliferated twice as much indicating that TSC1 supported regeneration of the OLP population after the insult. Olig2-mRNA expression showed 52% OLP survival in mice receiving a NMDA injection and increased to 78% when TSC1 + NMDA were injected simultaneously and ventricular size was reduced by TSC1. Furthermore, in striatal slices TSC1 reduced the inward currents induced by NMDA in medium-sized spiny neurons, demonstrating neuroprotection. Thus, white matter loss after excitotoxicity can be partially rescued as TSC1 conferred neuroprotection to preexisting OLP and regeneration via OLP proliferation. Furthermore, we showed that early TSC1 administration maximizes neuroprotection.

No MeSH data available.


Related in: MedlinePlus