epothilone-a and Spinal-Cord-Injuries

Spinal cord microcirculation plays an important role in maintaining the function of spinal cord neurons and other cells. Previous studies have largely focused on the ability of microtubule stabilization to inhibit the fibroblast migration and promote axon regeneration after spinal cord injury (SCI). However, the effect of microtubule stabilization treatment on microcirculation reconstruction after SCI remains unclear. By using immunofluorescence, we found that microtubule stabilization treatment improved microcirculation reconstruction via increasing the number of microvessels, pericytes, and the perfused microvessels after SCI. To clarify the underlying mechanisms, rat brain microvascular endothelial cells and pericytes were subjected to glucose oxygen deprivation. By using flow cytometry and western blotting, we found that microtubule stabilization treatment inhibited apoptosis and migration of endothelial cells and pericytes but promoted proliferation and survival of endothelial cells and pericytes through upregulated expression of vascular endothelial growth factor A (VEGFA), VEGF receptor 2, platelet-derived growth factor-B (PDGFB), PDGF receptor β, and angiopoietin-1 after SCI. Taken together, this study provides evidence for the mechanisms underlying the promotion of microcirculation reconstruction after SCI by microtubule stabilization treatment. Importantly, this study suggests the potential of microtubule stabilization as a therapeutic target to reduce microcirculation dysfunction after SCI in the clinic.

Topics: Animals; Apoptosis; Cell Hypoxia; Cell Movement; Cells, Cultured; Endothelial Cells; Epothilones; Female; Glucose; Microcirculation; Microtubules; Pericytes; Platelet-Derived Growth Factor; Rats; Rats, Sprague-Dawley; Receptors, Platelet-Derived Growth Factor; Receptors, Vascular Endothelial Growth Factor; Spinal Cord; Spinal Cord Injuries; Tubulin Modulators; Vascular Endothelial Growth Factor A

Spinal cord injury (SCI) causes motor and sensory deficits and is currently considered an incurable disease. We have previously reported that administration of anti-High Mobility Group Box-1 monoclonal antibody (anti-HMGB1 mAb) preserved lesion area and improved locomotion recovery in mouse model of SCI. In order to further enhance the recovery, we here examined combinatorial treatment of anti-HMGB1 mAb and epothilone B (Epo B), which has been reported to promote axon regeneration. This combinatorial treatment significantly increased hindlimb movement compared with anti-HMGB1 mAb alone, although Epo B alone failed to increase functional recovery. These results are in agreement with that anti-HMGB1 mAb alone was able to decrease the lesion area spreading and increase the surviving neuron numbers around the lesion, whereas Epo B facilitated axon outgrowth only in combination with anti-HMGB1 mAb, suggesting that anti-HMGB1 mAb-dependent tissue preservation is necessary for Epo B to exhibit its therapeutic effect. Taken together, the combinatorial treatment can be considered as a novel and clinically applicable strategy for SCI.

Topics: Animals; Antibodies, Monoclonal; Axons; Epothilones; Mice; Nerve Regeneration; Recovery of Function; Spinal Cord; Spinal Cord Injuries

Microtubule-stabilizing agents have been demonstrated to modulate axonal sprouting during neuronal disease. One such agent, Epothilone D, has been used to treat spinal cord injury (SCI) by promoting axonal sprouting at the lesion site after SCI. However, the role of Epothilone D in the differentiation of neural stem cells (NSCs) in SCI repair is unknown. In the present study, we mainly explored the effects and mechanisms of Epothilone D on the neuronal differentiation of NSCs and revealed a potential new SCI treatment.. In vitro differentiation assays, western blotting, and quantitative real-time polymerase chain reaction were used to detect the effects of Epothilone D on NSC differentiation. Retrograde tracing using a pseudotyped rabies virus was then used to detect neuronal circuit construction. RNA sequencing (RNA-Seq) was valuable for exploring the target gene involved in the neuronal differentiation stimulated by Epothilone D. In addition, lentivirus-induced overexpression and RNA interference technology were applied to demonstrate the function of the target gene. Last, an Apol8-NSC-linear ordered collagen scaffold (LOCS) graft was prepared to treat a mouse model of SCI, and functional and electrophysiological evaluations were performed.. We first revealed that Epothilone D promoted the neuronal differentiation of cultured NSCs and facilitated neuronal relay formation in the injured site after SCI. Furthermore, the RNA-Seq results demonstrated that Apol8 was upregulated during Epothilone D-induced neuronal relay formation. Lentivirus-mediated Apol8 overexpression in NSCs (Apol8-NSCs) promoted NSC differentiation toward neurons, and an Apol8 interference assay showed that Apol8 had a role in promoting neuronal differentiation under the induction of Epothilone D. Last, Apol8-NSC transplantation with LOCS promoted the neuronal differentiation of transplanted NSCs in the lesion site as well as synapse formation, thus improving the motor function of mice with complete spinal cord transection.. Epothilone D can promote the neuronal differentiation of NSCs by upregulating Apol8, which may provide a promising therapeutic target for SCI repair.

Topics: Animals; Cell Differentiation; Epothilones; Mice; Neural Stem Cells; Neurons; Recovery of Function; Spinal Cord; Spinal Cord Injuries; Up-Regulation

Following a spinal cord injury (SCI) a growth aversive environment forms, consisting of a fibroglial scar and inhibitory factors, further restricting the already low intrinsic growth potential of injured adult central nervous system (CNS) neurons. Previous studies have shown that local administration of the microtubule-stabilizing drug paclitaxel or epothilone B (Epo B) reduce fibrotic scar formation and axonal dieback as well as induce axonal growth/sprouting after SCI. Likewise, systemic administration of Epo B promoted functional recovery. In this study, we investigated the effects of epothilone D (Epo D), an analog of Epo B with a possible greater therapeutic index, on fibrotic scarring, axonal sprouting and functional recovery after SCI. Delayed systemic administration of Epo D after a moderate contusion injury (150 kDyn) in female Fischer 344 rats resulted in a reduced number of footfalls when crossing a horizontal ladder at 4 and 8 weeks post-injury. Hindlimb motor function assessed with the BBB open field locomotor rating scale and Catwalk gait analysis were not significantly altered. Moreover, formation of laminin positive fibrotic scar tissue and 5-HT positive serotonergic fiber length caudal to the lesion site were not altered after treatment with Epo D. These findings recapitulate a functional benefit after systemic administration of a microtubule-stabilizing drug in rat contusion SCI.

Topics: Animals; Axons; Contusions; Epothilones; Female; Fibrosis; Hindlimb; Locomotion; Microtubules; Nerve Fibers; Nerve Regeneration; Psychomotor Performance; Rats; Rats, Inbred F344; Recovery of Function; Serotonin; Spinal Cord Injuries; Tubulin Modulators

Topics: Animals; Cytoskeleton; Epothilones; Hindlimb; Rats; Spinal Cord Injuries

The microtubule-stabilizing drug epothilone B (epoB) has shown potential value in the treatment of spinal cord injury (SCI) through diverse mechanisms. However, it remains elusive why a limited overall effect was observed. We aim to investigate the limiting factors underlying functional recovery promoted by epoB. The same SCI model treated by epoB was established as discussed previously. We used a cerebrospinal fluid (CSF) sample to assess the changes in cytokines in milieu of the SCI lesion site after epoB treatment. We then analyzed the source of cytokines, the state of microglia/macrophages/monocytes (M/Ms), and the recruitment of neutrophil in the lesion site by using the results of antibody array. Following these findings, we further evaluated the motor functional recovery caused by the reshaped microenvironment. Systemic administration of epoB significantly increased levels of several cytokines in the CSF of the rat SCI model; macrophage colony-stimulating factor (M-CSF) secreted by intact central nervous system (CNS) cells was one of the cytokines with increased levels. Along with epoB and other cytokines, M-CSF reshapes the SCI milieu by activating the microglias, killing bone marrow-derived macrophages, polarizing the M/M to M1 phenotype, and activating downstream cytokines to exacerbate the SCI injury, but it also increases the expression of neurotrophic factors. Anti-inflammatory therapy using a neutralizing antibody mix shows encouraging results. Using in vivo experiments, our findings indicate that epoB inhibits the SCI functional recovery in many ways by reshaping the milieu, which counteracts the therapeutic efficacy that led to the limited overall effectiveness.

Topics: Animals; Antibodies, Neutralizing; Astrocytes; Cell Line; Cell Polarity; Cytokines; Disease Models, Animal; Epothilones; Female; Locomotion; Macrophage Colony-Stimulating Factor; Macrophages; Microglia; Neutrophils; Phagocytosis; Rats; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord Injuries; T-Lymphocytes

After central nervous system (CNS) injury, inhibitory factors in the lesion scar and poor axon growth potential prevent axon regeneration. Microtubule stabilization reduces scarring and promotes axon growth. However, the cellular mechanisms of this dual effect remain unclear. Here, delayed systemic administration of a blood-brain barrier-permeable microtubule-stabilizing drug, epothilone B (epoB), decreased scarring after rodent spinal cord injury (SCI) by abrogating polarization and directed migration of scar-forming fibroblasts. Conversely, epothilone B reactivated neuronal polarization by inducing concerted microtubule polymerization into the axon tip, which propelled axon growth through an inhibitory environment. Together, these drug-elicited effects promoted axon regeneration and improved motor function after SCI. With recent clinical approval, epothilones hold promise for clinical use after CNS injury.

Topics: Animals; Axons; Cell Movement; Cell Polarity; Cicatrix; Epothilones; Fibroblasts; Humans; Meninges; Motor Activity; Nerve Regeneration; Neurons; Rats; Spinal Cord Injuries; Tubulin Modulators

Topics: Animals; Axons; Cicatrix; Epothilones; Humans; Nerve Regeneration; Spinal Cord Injuries; Tubulin Modulators

Topics: Animals; Axons; Cicatrix; Epothilones; Humans; Nerve Regeneration; Spinal Cord Injuries; Tubulin Modulators