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Fgf-2 in astroglial cells during vertebrate spinal cord recovery.

Fahmy GH, Moftah MZ - Front Cell Neurosci (2010)

Bottom Line: Our results show that spinal cord injury triggers a significant increase in FGF-2 immunoreactivity in reactive astrocytes at sites of insult.In addition, these results were time-dependent.Therefore, we suggest that FGF-2 may be involved in cell proliferation and/or astroglial cells differentiation after body spinal cord transection, and could thus play an important role in locomotion recovery.

View Article: PubMed Central - PubMed

Affiliation: Zoology Department, Faculty of Science, Alexandria University Alexandria, Egypt.

ABSTRACT
Fibroblast growth factor-2 is a pleiotrophic cytokine with neurotrophic and gliogenic properties. It is known to regulate CNS injury responses, which include transformation of reactive astrocytes, neurogenesis, and promotion of neurotrophic activities. In the brain, it is localized in astrocytes and discrete neuronal populations. Following both central and peripheral nervous system injury, astrocytes become reactive. These activated cells undergo hypertrophy. A key indicator of astrocyte activation is the increased accumulation of intermediate filaments composed of glial fibrillary acidic protein (GFAP). Following physical insult of brain or spinal cord, reactive astrocytes show increased FGF-2 immunoreactivity. Thus, FGF-2 appears to participate in astrocytic differentiation and proliferation and a good candidate for astrocytic function regulation in healthy, injured, or diseased CNS. To further investigate the cellular mechanisms underlying FGF-2 restorative actions and to analyze the changes within astroglial cells, we studied the localization of GFAP and FGF-2 in adult intact and injured Pleurodeles CNS. Our results show that spinal cord injury triggers a significant increase in FGF-2 immunoreactivity in reactive astrocytes at sites of insult. In addition, these results were time-dependent. Increase in FGF-2 immunoreactivity along the CNS axis, starting 1-week post-injury, was long-lasting extending to 6 weeks. This increase was accompanied by an increase in GFAP immunoreactivity in the same spatial pattern except in SC3 where its level was almost similar to sham-operated animals. Therefore, we suggest that FGF-2 may be involved in cell proliferation and/or astroglial cells differentiation after body spinal cord transection, and could thus play an important role in locomotion recovery.

No MeSH data available.


Related in: MedlinePlus

Fibroblast growth factor-2 labeling intensity in GFAP-positive ad GFAP-negative cells compared to sham-operated cases in the four examined regions of the CNS. The graph shows an evident colocalization between FGF-2 and GFAP in lesioned animals brainstem (A) and spinal cord (SC1: B and SC3: D) during the whole experimental period except in SC2 (the part of the spinal cord above the lesion site: C). Pattern of distribution of FGF-2 secreting cells was somehow similar in BS (A) and SC3 (D) but the sublesional part showed a much more significant colocalization. Stars are comparisons between columns and their previous ones except where noted.
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Figure 5: Fibroblast growth factor-2 labeling intensity in GFAP-positive ad GFAP-negative cells compared to sham-operated cases in the four examined regions of the CNS. The graph shows an evident colocalization between FGF-2 and GFAP in lesioned animals brainstem (A) and spinal cord (SC1: B and SC3: D) during the whole experimental period except in SC2 (the part of the spinal cord above the lesion site: C). Pattern of distribution of FGF-2 secreting cells was somehow similar in BS (A) and SC3 (D) but the sublesional part showed a much more significant colocalization. Stars are comparisons between columns and their previous ones except where noted.

Mentions: In all regions, there was an obvious FGF-2 expression in GFAP-positive and -negative cells. In order to better understand the activation process occurring in astrocytes, we measured the colocalization between FGF-2 and GFAP after lesion by assessing FGF-2 intensity in both types of cells in each region of the CNS. We found that in brainstem region, colocalization of both proteins was mainly evident during the 1st–2nd week after lesion (68.02 ± 1.6) compared to sham-operated animals (13.5 ± 5.5). This concomitant expression was significantly decreased (p < 0.001) in a long-lasting manner giving rise to a lesser degree of colocalization although significant (p < 0.001) compared to shams (Figure 5A, left). The very high FGF-2 labeling intensity seen in GFAP-negative cells (Figure 5A, right), 1 week post-op, implies that FGF-2 is not only secreted in astrocytes but also in neurones to induce astrocyte activation in the beginning of the recovery process.


Fgf-2 in astroglial cells during vertebrate spinal cord recovery.

Fahmy GH, Moftah MZ - Front Cell Neurosci (2010)

Fibroblast growth factor-2 labeling intensity in GFAP-positive ad GFAP-negative cells compared to sham-operated cases in the four examined regions of the CNS. The graph shows an evident colocalization between FGF-2 and GFAP in lesioned animals brainstem (A) and spinal cord (SC1: B and SC3: D) during the whole experimental period except in SC2 (the part of the spinal cord above the lesion site: C). Pattern of distribution of FGF-2 secreting cells was somehow similar in BS (A) and SC3 (D) but the sublesional part showed a much more significant colocalization. Stars are comparisons between columns and their previous ones except where noted.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2990542&req=5

Figure 5: Fibroblast growth factor-2 labeling intensity in GFAP-positive ad GFAP-negative cells compared to sham-operated cases in the four examined regions of the CNS. The graph shows an evident colocalization between FGF-2 and GFAP in lesioned animals brainstem (A) and spinal cord (SC1: B and SC3: D) during the whole experimental period except in SC2 (the part of the spinal cord above the lesion site: C). Pattern of distribution of FGF-2 secreting cells was somehow similar in BS (A) and SC3 (D) but the sublesional part showed a much more significant colocalization. Stars are comparisons between columns and their previous ones except where noted.
Mentions: In all regions, there was an obvious FGF-2 expression in GFAP-positive and -negative cells. In order to better understand the activation process occurring in astrocytes, we measured the colocalization between FGF-2 and GFAP after lesion by assessing FGF-2 intensity in both types of cells in each region of the CNS. We found that in brainstem region, colocalization of both proteins was mainly evident during the 1st–2nd week after lesion (68.02 ± 1.6) compared to sham-operated animals (13.5 ± 5.5). This concomitant expression was significantly decreased (p < 0.001) in a long-lasting manner giving rise to a lesser degree of colocalization although significant (p < 0.001) compared to shams (Figure 5A, left). The very high FGF-2 labeling intensity seen in GFAP-negative cells (Figure 5A, right), 1 week post-op, implies that FGF-2 is not only secreted in astrocytes but also in neurones to induce astrocyte activation in the beginning of the recovery process.

Bottom Line: Our results show that spinal cord injury triggers a significant increase in FGF-2 immunoreactivity in reactive astrocytes at sites of insult.In addition, these results were time-dependent.Therefore, we suggest that FGF-2 may be involved in cell proliferation and/or astroglial cells differentiation after body spinal cord transection, and could thus play an important role in locomotion recovery.

View Article: PubMed Central - PubMed

Affiliation: Zoology Department, Faculty of Science, Alexandria University Alexandria, Egypt.

ABSTRACT
Fibroblast growth factor-2 is a pleiotrophic cytokine with neurotrophic and gliogenic properties. It is known to regulate CNS injury responses, which include transformation of reactive astrocytes, neurogenesis, and promotion of neurotrophic activities. In the brain, it is localized in astrocytes and discrete neuronal populations. Following both central and peripheral nervous system injury, astrocytes become reactive. These activated cells undergo hypertrophy. A key indicator of astrocyte activation is the increased accumulation of intermediate filaments composed of glial fibrillary acidic protein (GFAP). Following physical insult of brain or spinal cord, reactive astrocytes show increased FGF-2 immunoreactivity. Thus, FGF-2 appears to participate in astrocytic differentiation and proliferation and a good candidate for astrocytic function regulation in healthy, injured, or diseased CNS. To further investigate the cellular mechanisms underlying FGF-2 restorative actions and to analyze the changes within astroglial cells, we studied the localization of GFAP and FGF-2 in adult intact and injured Pleurodeles CNS. Our results show that spinal cord injury triggers a significant increase in FGF-2 immunoreactivity in reactive astrocytes at sites of insult. In addition, these results were time-dependent. Increase in FGF-2 immunoreactivity along the CNS axis, starting 1-week post-injury, was long-lasting extending to 6 weeks. This increase was accompanied by an increase in GFAP immunoreactivity in the same spatial pattern except in SC3 where its level was almost similar to sham-operated animals. Therefore, we suggest that FGF-2 may be involved in cell proliferation and/or astroglial cells differentiation after body spinal cord transection, and could thus play an important role in locomotion recovery.

No MeSH data available.


Related in: MedlinePlus