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Post-paralysis tyrosine kinase inhibition with masitinib abrogates neuroinflammation and slows disease progression in inherited amyotrophic lateral sclerosis.

Trias E, Ibarburu S, Barreto-Núñez R, Babdor J, Maciel TT, Guillo M, Gros L, Dubreuil P, Díaz-Amarilla P, Cassina P, Martínez-Palma L, Moura IC, Beckman JS, Hermine O, Barbeito L - J Neuroinflammation (2016)

Bottom Line: Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown.We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations.Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11.400, Uruguay.

ABSTRACT

Background: In the SOD1(G93A) mutant rat model of amyotrophic lateral sclerosis (ALS), neuronal death and rapid paralysis progression are associated with the emergence of activated aberrant glial cells that proliferate in the degenerating spinal cord. Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown. We hypothesized that proliferation of aberrant glial cells is dependent on kinase receptor activation, and therefore, the tyrosine kinase inhibitor masitinib (AB1010) could potentially control neuroinflammation in the rat model of ALS.

Methods: The cellular effects of pharmacological inhibition of tyrosine kinases with masitinib were analyzed in cell cultures of microglia isolated from aged symptomatic SOD1(G93A) rats. To determine whether masitinib prevented the appearance of aberrant glial cells or modified post-paralysis survival, the drug was orally administered at 30 mg/kg/day starting after paralysis onset.

Results: We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations. In microglia cultures from symptomatic SOD1(G93A) spinal cords, masitinib prevented CSF-induced proliferation, cell migration, and the expression of inflammatory mediators. Oral administration of masitinib to SOD1(G93A) rats starting after paralysis onset decreased the number of aberrant glial cells, microgliosis, and motor neuron pathology in the degenerating spinal cord, relative to vehicle-treated rats. Masitinib treatment initiated 7 days after paralysis onset prolonged post-paralysis survival by 40 %.

Conclusions: These data show that masitinib is capable of controlling microgliosis and the emergence/expansion of aberrant glial cells, thus providing a strong biological rationale for its use to control neuroinflammation in ALS. Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.

No MeSH data available.


Related in: MedlinePlus

Masitinib inhibited microglia proinflammatory phenotype and prevented microglia migration and transformation into aberrant glial cells. a Real-time PCR analysis showed that the treatment with pharmacological concentration (1 μM) of masitinib during 72 h is sufficient to significantly reduce the expression of several genes involved in inflammatory processes. b A confluent monolayer was scratched to determine the migratory capacity of aberrant microglia. After 24 h, cells located between the dashed lines were counted. Vehicle-treated microglia covered most of the scratch after 24 h, while masitinib-treated cells showed significantly less migratory capacity. The inset shows the open space in the monolayer immediately after making the scratch (scale bar 20 μm). The graph to the right shows the quantitative analysis of migration. c Masitinib prevented microglia transformation into aberrant glial cells in a dose-dependent manner when compared with vehicle-treated cultures. Note how after 12 days in vitro, microglia transition to a flat astrocyte-like cell that reach confluence. Masitinib significantly prevented this transformation and few microglia cells transitioned into aberrant glial cells (scale bar 10 μm). The graph to the right represents the quantitative analysis showing the number of aberrant glial cells after 12 days in vitro (12DIV). All data are expressed as mean ± SEM *p < 0.01
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Fig2: Masitinib inhibited microglia proinflammatory phenotype and prevented microglia migration and transformation into aberrant glial cells. a Real-time PCR analysis showed that the treatment with pharmacological concentration (1 μM) of masitinib during 72 h is sufficient to significantly reduce the expression of several genes involved in inflammatory processes. b A confluent monolayer was scratched to determine the migratory capacity of aberrant microglia. After 24 h, cells located between the dashed lines were counted. Vehicle-treated microglia covered most of the scratch after 24 h, while masitinib-treated cells showed significantly less migratory capacity. The inset shows the open space in the monolayer immediately after making the scratch (scale bar 20 μm). The graph to the right shows the quantitative analysis of migration. c Masitinib prevented microglia transformation into aberrant glial cells in a dose-dependent manner when compared with vehicle-treated cultures. Note how after 12 days in vitro, microglia transition to a flat astrocyte-like cell that reach confluence. Masitinib significantly prevented this transformation and few microglia cells transitioned into aberrant glial cells (scale bar 10 μm). The graph to the right represents the quantitative analysis showing the number of aberrant glial cells after 12 days in vitro (12DIV). All data are expressed as mean ± SEM *p < 0.01

Mentions: As predicted by the hypertrophic and phagocytic morphology, primary cultured microglia from symptomatic SOD1G93A spinal cords displayed a robust transcriptional activity for inflammatory genes. After exposure to masitinib during 72 h, the transcription of several genes highly involved in neuroinflammation decreased more than 50 %. In particular, relevant inflammatory transcripts such as IL1β, IL6, Iba1, and Cox2 were downregulated by approximately 80 % (Fig. 2a). In addition, Fig. 2b shows that masitinib inhibited by more than 50 %, the ability of microglia to migrate across a scratch made in the culture dish in low FBS conditions.Fig. 2


Post-paralysis tyrosine kinase inhibition with masitinib abrogates neuroinflammation and slows disease progression in inherited amyotrophic lateral sclerosis.

Trias E, Ibarburu S, Barreto-Núñez R, Babdor J, Maciel TT, Guillo M, Gros L, Dubreuil P, Díaz-Amarilla P, Cassina P, Martínez-Palma L, Moura IC, Beckman JS, Hermine O, Barbeito L - J Neuroinflammation (2016)

Masitinib inhibited microglia proinflammatory phenotype and prevented microglia migration and transformation into aberrant glial cells. a Real-time PCR analysis showed that the treatment with pharmacological concentration (1 μM) of masitinib during 72 h is sufficient to significantly reduce the expression of several genes involved in inflammatory processes. b A confluent monolayer was scratched to determine the migratory capacity of aberrant microglia. After 24 h, cells located between the dashed lines were counted. Vehicle-treated microglia covered most of the scratch after 24 h, while masitinib-treated cells showed significantly less migratory capacity. The inset shows the open space in the monolayer immediately after making the scratch (scale bar 20 μm). The graph to the right shows the quantitative analysis of migration. c Masitinib prevented microglia transformation into aberrant glial cells in a dose-dependent manner when compared with vehicle-treated cultures. Note how after 12 days in vitro, microglia transition to a flat astrocyte-like cell that reach confluence. Masitinib significantly prevented this transformation and few microglia cells transitioned into aberrant glial cells (scale bar 10 μm). The graph to the right represents the quantitative analysis showing the number of aberrant glial cells after 12 days in vitro (12DIV). All data are expressed as mean ± SEM *p < 0.01
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4940876&req=5

Fig2: Masitinib inhibited microglia proinflammatory phenotype and prevented microglia migration and transformation into aberrant glial cells. a Real-time PCR analysis showed that the treatment with pharmacological concentration (1 μM) of masitinib during 72 h is sufficient to significantly reduce the expression of several genes involved in inflammatory processes. b A confluent monolayer was scratched to determine the migratory capacity of aberrant microglia. After 24 h, cells located between the dashed lines were counted. Vehicle-treated microglia covered most of the scratch after 24 h, while masitinib-treated cells showed significantly less migratory capacity. The inset shows the open space in the monolayer immediately after making the scratch (scale bar 20 μm). The graph to the right shows the quantitative analysis of migration. c Masitinib prevented microglia transformation into aberrant glial cells in a dose-dependent manner when compared with vehicle-treated cultures. Note how after 12 days in vitro, microglia transition to a flat astrocyte-like cell that reach confluence. Masitinib significantly prevented this transformation and few microglia cells transitioned into aberrant glial cells (scale bar 10 μm). The graph to the right represents the quantitative analysis showing the number of aberrant glial cells after 12 days in vitro (12DIV). All data are expressed as mean ± SEM *p < 0.01
Mentions: As predicted by the hypertrophic and phagocytic morphology, primary cultured microglia from symptomatic SOD1G93A spinal cords displayed a robust transcriptional activity for inflammatory genes. After exposure to masitinib during 72 h, the transcription of several genes highly involved in neuroinflammation decreased more than 50 %. In particular, relevant inflammatory transcripts such as IL1β, IL6, Iba1, and Cox2 were downregulated by approximately 80 % (Fig. 2a). In addition, Fig. 2b shows that masitinib inhibited by more than 50 %, the ability of microglia to migrate across a scratch made in the culture dish in low FBS conditions.Fig. 2

Bottom Line: Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown.We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations.Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.

View Article: PubMed Central - PubMed

Affiliation: Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11.400, Uruguay.

ABSTRACT

Background: In the SOD1(G93A) mutant rat model of amyotrophic lateral sclerosis (ALS), neuronal death and rapid paralysis progression are associated with the emergence of activated aberrant glial cells that proliferate in the degenerating spinal cord. Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown. We hypothesized that proliferation of aberrant glial cells is dependent on kinase receptor activation, and therefore, the tyrosine kinase inhibitor masitinib (AB1010) could potentially control neuroinflammation in the rat model of ALS.

Methods: The cellular effects of pharmacological inhibition of tyrosine kinases with masitinib were analyzed in cell cultures of microglia isolated from aged symptomatic SOD1(G93A) rats. To determine whether masitinib prevented the appearance of aberrant glial cells or modified post-paralysis survival, the drug was orally administered at 30 mg/kg/day starting after paralysis onset.

Results: We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations. In microglia cultures from symptomatic SOD1(G93A) spinal cords, masitinib prevented CSF-induced proliferation, cell migration, and the expression of inflammatory mediators. Oral administration of masitinib to SOD1(G93A) rats starting after paralysis onset decreased the number of aberrant glial cells, microgliosis, and motor neuron pathology in the degenerating spinal cord, relative to vehicle-treated rats. Masitinib treatment initiated 7 days after paralysis onset prolonged post-paralysis survival by 40 %.

Conclusions: These data show that masitinib is capable of controlling microgliosis and the emergence/expansion of aberrant glial cells, thus providing a strong biological rationale for its use to control neuroinflammation in ALS. Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.

No MeSH data available.


Related in: MedlinePlus