FGF-2 and Anosmin-1 are selectively expressed in different types of multiple sclerosis lesions - PubMed (original) (raw)
FGF-2 and Anosmin-1 are selectively expressed in different types of multiple sclerosis lesions
Diego Clemente et al. J Neurosci. 2011.
Abstract
Multiple sclerosis is a demyelinating disease that affects ≈ 2,000,000 people worldwide. In the advanced stages of the disease, endogenous oligodendrocyte precursors cannot colonize the lesions or differentiate into myelinating oligodendrocytes. During development, both FGF-2 and Anosmin-1 participate in oligodendrocyte precursor cell migration, acting via the FGF receptor 1 (FGFR1). Hence, we performed a histopathological and molecular analysis of these developmental modulators in postmortem tissue blocks from multiple sclerosis patients. Accordingly, we demonstrate that the distribution of FGF-2 and Anosmin-1 varies between the different types of multiple sclerosis lesions: FGF-2 is expressed only within active lesions and in the periplaque of chronic lesions, whereas Anosmin-1 is upregulated within chronic lesions and is totally absent in active lesions. We show that the endogenous oligodendrocyte precursor cells recruited toward chronic-active lesions express FGFR1, possibly in response to the FGF-2 produced by microglial cells in the periplaque. Also in human tissue, FGF-2 is upregulated in perivascular astrocytes in regions of the normal-appearing gray matter, where the integrity of the blood-brain barrier is compromised. In culture, FGF-2 and Anosmin-1 influence adult mouse oligodendrocyte precursor cell migration in the same manner as at embryonic stages, providing an explanation for the histopathological observations: FGF-2 attracts/enhances its migration, which is hindered by Anosmin-1. We propose that FGF-2 and Anosmin-1 are markers for the histopathological type and the level of inflammation of multiple sclerosis lesions, and that they may serve as novel pharmacogenetic targets to design future therapies that favor effective remyelination and protect the blood-brain barrier.
Figures
Figure 1.
FGF-2 is overexpressed in the tissue of MS patients but not in all types of MS lesions. A, Western blot analysis was performed using an FGF-2 polyclonal antibody on cerebral cortex protein extracts (100 μg of total protein each) from control (Ct) and MS patients. α-Tubulin was used as a loading control. B, C, Panoramic views of a pre-phagocytic area (PA) labeled with HLA-DR (B, brown staining), which presented a group of activated microglial cells with no signs of cell infiltration, and FGF-2 (C, brown staining) and the myelin staining eriochrome cyanine (B, C, blue staining). D, General view of a portion of one shadow plaque (SP). The density of FGF-2+ cells (brown staining) is similar in the shadow plaque to that in the adjacent NAWM. E, F, Examples of FGF-2+ cells (with the morphology of resting microglia) from a pre-phagocytic area (E) or within a shadow plaque (F). G–I, FGF-2+ cells within the shadow plaque are also positive for the macrophage/microglial marker CD68. Scale bars: B–D, 200 μm; E, F, 10 μm; G–I, 12 μm. B, C, and E are from case MS125; D and F–I are from case MS60.
Figure 2.
Expression pattern of FGF-2 in active and chronic-active lesions. A, Panoramic view of an active lesion with many FGF-2+ infiltrates. B, High-magnification image showing several FGF-2+ cells with macrophage morphology from the core of an active lesion. C, In the border of the same lesion, FGF-2+ cells showed intermediate shapes between macrophage and activated microglia. D–I, Double labeling with the inflammatory marker HLA-DR and the microglia/macrophage marker CD68 of both cell types, within the core (D–F) and at the border (G–I) of an active lesion. J, General view of a chronic-active lesion where a higher density of FGF-2+ cells was detected within the demyelinating area (periplaque) than in the adjacent NAWM. In contrast, no FGF-2 immunoreactivity was detected within the demyelinated plaque itself. K–L, High-magnification images of two of the FGF-2+ cells observed in the periplaque of a chronic-active lesion showing a well vacuolated cytoplasm and several processes. M–R, Examples of FGF-2+ cells (M, P) double labeled with HLA-DR (N, O) or the microglia/macrophage marker CD68 (Q, R). Scale bars: A, 120 μm; B, C, M–O, 7 μm; D–F, 6 μm; G–I, 8 μm; J, 100 μm; K–L, P–R, 10 μm. A–I are from case MS249; J–R are from case MS106.
Figure 3.
Perivascular astrocytes overexpress FGF-2 in the cerebral cortex of MS patients. A, B, Parallel sections of the same region of a block from one MS patient where a general upregulation of FGF-2 in perivascular astrocytes (A, arrows) was restricted to the NAGM area with no signs of demyelination in the contiguous NAWM (B). C, Detailed view of two FGF-2+ cells, one in contact with a blood vessel (black arrow). D–F, Double labeling (white arrows) of FGF-2 (D) and GFAP, a marker for astrocytes (E), which confirms their coexpression (F). G–I, In gray matter of controls, where FGF-2-immunoreactive astrocytes were absent (G), a continuous linear ZO-1 immunoreactivity could be seen (H–I). J, L, Association of FGF-2+ perivascular astrocytes within the NAGM of a MS patient with a blood vessel contacting process (J, L, arrow). K, L, ZO-1 immunoreactivity displayed a continuous but more diffuse expression pattern in the NAGM of MS patients. EC, Eriochrome cyanine. Scale bars: A, B, 800 μm; C, 25 μm; D–F, 10 μm; G–L, 15 μm. A, B, and J–L are from case MS125; C–F are from case MS106; G–I are from case CO41.
Figure 4.
Anosmin-1 is selectively expressed within chronic-active and chronic-inactive demyelinating plaques of MS patients. A–F, Images of parallel sections with one active (Ac in A, D), one chronic-active (C-A in B, E), and one chronic-inactive (C-I in C, F) plaques stained with HLA-DR followed by the myelin-specific eriochrome cyanine staining (A–C) and immunostained for Anosmin-1 (D–F). G, Anosmin-1-immunoreactive perivascular infiltrates (asterisk) from an MS patient in close proximity to an Anosmin-1-containing lesion. H, High-magnification image of one group of Anosmin-1+ perivascular blood cells within a chronic lesion. I, Some axons express Anosmin-1 in their nude segment within a chronic-active MS lesion. J–L, Within chronic lesions, some of the β-III-Tubulin+ axons showed Anosmin-1 immunoreactivity (arrows). M–O, In the NAWM of the same patient, no Anosmin-1+ axons were detected. Scale bars: A–F, 400 μm; G, 100 μm; H, I, 25 μm; J–L, 20 μm; M–O, 17 μm. A, D, and J–O are from case MS342; B and E are from case MS125; C, and F–I are from case MS149.
Figure 5.
FGFR1 distribution in controls and MS patients. A, A detailed view of one FGFR1+ cell from the white matter of a control patient. B–D, Confocal images showing one astrocyte positively immunostained for FGFR1 (red) and GFAP (green). E–H, Panoramic view of a chronic-active lesion where FGFR1+/PDGFRα+ OPCs within the periplaque and in the NAWM (arrowheads) and a FGFR1−/ PDGFRα+ OPC in the periplaque (arrows) were observed. I–L, A FGFR1+ OPC within the periplaque of a chronic-active lesion of a MS patient. M–P, A detailed image of a FGFR1+/GFAP+ astrocyte (arrowheads) and a PDGFRα+/FGFR1− OPC (arrows) within the NAWM of a MS patient. Q, R, Quantification of the density of OPCs (Q) or OPCs double labeled for FGFR1 (R) in the plaque, periplaque, and its adjacent NAWM from nine chronic-active lesions belonging to MS40, MS46, MS106, and MS125. There were no OPCs detected in the plaque, while the periplaque and NAWM showed statistically similar numbers of OPCs (Q). In contrast, the number of FGFR1+ OPCs was significantly higher in the periplaque than in its adjacent NAWM. Within the periplaque, the number of FGFR1+ OPCs was significantly higher than that of FGFR1− OPCs. One-way ANOVA followed by Student's t test (represented): *p < 0.05. S, A group of FGFR1+ perivascular glial cells from the gray matter of a MS patient. T–V, Confocal images of an astrocyte double immunostained for FGFR1 (red) and GFAP (green) with a blood vessel contacting process from the gray matter of an MS patient. Scale bars: A, 10 μm; B–D, 22 μm; E–H, 45 μm; I–P, 15 μm; S, 50 μm; T–V, 8 μm. A–D are from case CO25; E–P are from case MS106; S–V are from case MS149.
Figure 6.
In vitro studies on FGF-2/Anosmin-1-mediated activity in adult OPCs. A–C, Characterization of OPCs isolated from mouse adult cerebral cortex double immunostained for NG2/PDGFRα. D–I, Representative images of the A2B5+/olig2+ migratory cells under different experimental conditions. J, Histogram showing the percentage of migrating OPCs from adult mice quantified after culturing under standard conditions (CHO-CT) or in the presence of various modulators as indicated, including the FGFR blocker SU5402. Treatment with FGF-2 alone (white bars) led to a significant increase in the number of migrating OPCs, while that with Anosmin-1 alone (CHO-A1, light gray bars) had the opposite effect when compared withcontrol conditions (black bars). Combined treatment with FGF-2 and Anosmin-1 (dark gray bars) gave rise to an intermediate number of migrating OPCs. The effects of FGF-2 and Anosmin-1 were blocked in the presence of SU5402. Student's t test results are represented as follows: **p < 0.01; ***p < 0.001 with respect to control conditions (###p < 0.001, also vs control conditions). Scale bar: A–I, 25 μm.
Figure 7.
Schematic representation of the putative functional implications of the FGF-2/FGFR1/Anosmin-1 system in MS. A, In active lesions (where remyelination is possible), there is an increment in the density of FGF-2 expressing macrophages and FGFR1+ OPCs, whereas Anosmin-1 is absent. B, In contrast, in chronic-active lesions (where remyelination rarely exists and is mainly restricted to the periplaque), the molecular environment is drastically different: FGF-2 expression is limited to the macrophages/microglia in the periplaque, probably attracting FGFR1+ OPCs toward the lesion; on the contrary, the expression of Anosmin-1 is widespread throughout the core of the lesion and may be preventing remyelination.
References
- Arnett HA, Fancy SP, Alberta JA, Zhao C, Plant SR, Kaing S, Raine CS, Rowitch DH, Franklin RJ, Stiles CD. bHLH transcription factor Olig1 is required to repair demyelinated lesions in the CNS. Science. 2004;306:2111–2115. -PubMed
- Back SA, Tuohy TM, Chen H, Wallingford N, Craig A, Struve J, Luo NL, Banine F, Liu Y, Chang A, Trapp BD, Bebo BF, Jr, Rao MS, Sherman LS. Hyaluronan accumulates in demyelinated lesions and inhibits oligodendrocyte progenitor maturation. Nat Med. 2005;11:966–972. -PubMed
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical
Miscellaneous