Intracarotid Infusion of Mesenchymal Stem Cells in an Animal Model of Parkinson's Disease, Focusing on Cell Distribution and Neuroprotective and Behavioral Effects.
ABSTRACT: Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for Parkinson's disease (PD) and systemic administration of these cells has been tested in preclinical and clinical studies. However, no information on survival and actual capacity of MSCs to reach the brain has been provided. In this study, we evaluated homing of intraarterially infused rat MSCs (rMSCs) in the brain of rats bearing a 6-hydroxydopamine (6-OHDA)-induced lesion of the nigrostriatal tract, to establish whether the toxin-induced damage is sufficient to grant MSC passage across the blood-brain barrier (BBB) or if a transient BBB disruption is necessary. The rMSC distribution in peripheral organs and the effects of cell infusion on neurodegenerative process and motor deficits were also investigated. rMSCs were infused 14 days after 6-OHDA injection. A hyperosmolar solution of mannitol was used to transiently permeabilize the BBB. Behavioral impairment was assessed by adjusting step test and response to apomorphine. Animals were sacrificed 7 and 28 days after cell infusion. Our work shows that appreciable delivery of rMSCs to the brain of 6-OHDA-lesioned animals can be obtained only after mannitol pretreatment. A notable percentage of infused cells accumulated in peripheral organs. Infusion of rMSCs did not modify the progression of 6-OHDA-induced damage or the motor impairment at the stepping test, but induced progressive normalization of the pathological response (contralateral turning) to apomorphine administration. These findings suggest that many aspects should be further investigated before considering any translation of MSC systemic administration into the clinical setting for PD treatment.This study demonstrates that mesenchymal stem cells infused through the carotid artery do not efficiently cross the blood-brain barrier in rats with a Parkinson's disease-like degeneration of nigrostriatal neurons, unless a permeabilizing agent (e.g., mannitol) is used. The infusion did not reduce the neuronal damage and associated motor impairment, but abolished the motor abnormalities these animals typically show when challenged with a dopaminergic agonist. Therefore, although arterially infused mesenchymal stem cells did not show neurorestorative effects in this study's Parkinson's disease model, they appeared to normalize the pathological responsiveness of striatal neurons to dopaminergic stimulation. This capability should be further explored in future studies.
Project description:Recently, we showed that intracerebroventricular (IC) transplantation of human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) significantly attenuates posthemorrhagic hydrocephalus (PHH) and brain damage after severe IVH in newborn rats. This study was performed to determine the optimal route for transplanting MSCs for severe IVH by comparing IC transplantation, intravenous (IV) transplantation, and IV transplantation plus mannitol infusion. Severe IVH was induced by injecting 100 uL of blood into each ventricle of Sprague-Dawley rats on postnatal day 4 (P4). After confirming severe IVH with brain magnetic resonance imaging (MRI) at P5, human UCB-derived MSCs were transplanted at P6 by an IC route (1×105), an IV route (5×105), or an IV route with mannitol infused. Follow-up brain MRIs and rotarod tests were performed. At P32, brain tissue samples were obtained for biochemical and histological analyses. Although more MSCs localized to the brain after IC than after IV delivery, both methods were equally effective in preventing PHH; attenuating impaired rotarod test; increasing the number of TUNEL-positive cells, inflammatory cytokines, and astrogliosis; and reducing corpus callosal thickness and myelin basic protein expression after severe IVH regardless of mannitol co-infusion. Despite the superior delivery efficacy with IC than with the IV route, both IC and IV transplantation of MSCs had equal therapeutic efficacy in protecting against severe IVH. These findings suggest that the less invasive IV route might be a good alternative for clinically unstable, very preterm infants that cannot tolerate a more invasive IC delivery of MSCs.
Project description:Amyotrophic lateral sclerosis (ALS) is a neurodegenerative fatal disorder in which motor neurons within the brain and spinal cord degenerate. A single infusion of mesenchymal stem cells (MSCs) delays disease progression by protecting motor neurons and restoring the blood-spinal cord barrier in the SOD1G93A transgenic ALS rat model. However, the therapeutic effect of a single infusion of MSCs is transient and does not block disease progression. In this study, we demonstrated that repeated administration of MSCs (weekly, four times) increased the survival period, protected motor functions, and reduced deterioration of locomotor activity compared to a single infusion and vehicle infusion, after which rats displayed progressive deterioration of hind limb function. We also compared the days until gait ability was lost in rats and found that the repeated-infused group maintained gait ability compared to the single-infusion and vehicle-infusion groups. These results suggest that repeated administration of MSCs may prevent the deterioration of motor function and extend the lifespan in ALS.
Project description:Recent evidence has demonstrated that remote responses in the brain, as well as local responses in the injured spinal cord, can be induced after spinal cord injury (SCI). Intravenous infusion of mesenchymal stem cells (MSCs) has been shown to provide functional improvements in SCI through local therapeutic mechanisms that provide neuroprotection, stabilization of the blood-spinal cord barrier, remyelination, and axonal sprouting. In the present study, we examined the brain response that might be associated with the functional improvements induced by the infused MSCs after SCI. Genome-wide RNA profiling was performed in the motor cortex of SCI rats at 3 days post-MSC or vehicle infusion. Then, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) data revealed that the "behaviorally-associated differentially expressed genes (DEGs)" were identified by the Pearson's correlation analysis with the behavioral function, suggesting that the "behaviorally-associated DEGs" may be related to the functional recovery after systemic infusion of MSCs in SCI. These results suggested that the infused MSCs alter the gene expression signature in the brain and that these expression changes may contribute to the improved function in SCI.
Project description:As the majority of therapeutic agents do not cross the blood-brain barrier (BBB), transient BBB opening (BBBO) is one strategy to enable delivery into the brain for effective treatment of CNS disease. Intra-arterial infusion of the hyperosmotic agent mannitol reversibly opens the BBB; however, widespread clinical use has been limited due to the variability in outcomes. The current model for mannitol-induced BBBO assumes a transient but homogeneous increase in permeability; however, the details are poorly understood. To elucidate the mechanism of hyperosmotic opening at the cellular level, we developed a tissue-engineered microvessel model using stem cell-derived human brain microvascular endothelial cells (BMECs) perturbed with clinically relevant mannitol doses. This model recapitulates physiological shear stress, barrier function, microvessel geometry, and cell-matrix interactions. Using live-cell imaging, we show that mannitol results in dose-dependent and spatially heterogeneous increases in paracellular permeability through the formation of transient focal leaks. Additionally, we find that the degree of BBB opening and subsequent recovery is modulated by treatment with basic fibroblast growth factor. These results show that tissue-engineered BBB models can provide insight into the mechanisms of BBBO and hence improve the reproducibility of hyperosmotic therapies for treatment of CNS disease.
Project description:The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated.
Project description:The ability of monocytes and monocyte-derived macrophages (MDM) to travel towards chemotactic gradient, traverse tissue barriers, and accumulate precisely at diseased sites makes them attractive candidates as drug carriers and therapeutic gene delivery vehicles targeting the brain, where treatments are often hampered by the blockade of the blood brain barrier (BBB). This study was designed to fully establish an optimized cell-based delivery system using monocytes and MDM, by evaluating their homing efficiency, engraftment potential, as well as carriage and delivery ability to transport nano-scaled particles and exogenous genes into the brain, following the non-invasive intravenous (IV) cell adoptive transfer in an acute neuroinflammation mouse model induced by intracranial injection of Escherichia coli lipopolysaccharides. We demonstrated that freshly isolated monocytes had superior inflamed-brain homing ability over MDM cultured in the presence of macrophage colony stimulating factor. In addition, brain trafficking of IV infused monocytes was positively correlated with the number of adoptive transferred cells, and could be further enhanced by transient disruption of the BBB with IV administration of Mannitol, Bradykinin or Serotonin right before cell infusion. A small portion of transmigrated cells was detected to differentiate into IBA-1 positive cells with microglia morphology in the brain. Finally, with the use of superparamagnetic iron oxide nanoparticles SHP30, the ability of nanoscale agent-carriage monocytes to enter the inflamed brain region was validated. In addition, lentiviral vector DHIV-101 was used to introduce green fluorescent protein (GFP) gene into monocytes, and the exogenous GFP gene was detected in the brain at 48 hours following IV infusion of the transduced monocytes. All together, our study has set up the optimized conditions for the more-in-depth tests and development of monocyte-mediated delivery, and our data supported the notion to use monocytes as a non-invasive cell-based delivery system for the brain.
Project description:Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra. Several treatments for PD have focused on the management of physical symptoms using dopaminergic agents. However, these treatments induce various adverse effects, including hallucinations and cognitive impairment, owing to non-targeted brain delivery, while alleviating motor symptoms. Furthermore, these therapies are not considered ultimate cures owing to limited brain self-repair and regeneration abilities. In the present study, we aimed to investigate the therapeutic potential of human adipose-derived stem cells (hASCs) using magnetic nanoparticles in a 6-hydroxydopamine (6-OHDA)-induced PD mouse model. We used the Maestro imaging system and magnetic resonance imaging (MRI) for in vivo tracking after transplantation of magnetic nanoparticle-loaded hASCs to the PD mouse model. The Maestro imaging system revealed strong hASCs signals in the brains of PD model mice. In particular, MRI revealed hASCs distribution in the substantia nigra of hASCs-injected PD mice. Behavioral evaluations, including apomorphine-induced rotation and rotarod performance, were significantly recovered in hASCs-injected 6-OHDA induced PD mice when compared with saline-treated counterparts. Herein, we investigated whether hASCs transplantation using magnetic nanoparticles recovered motor functions through targeted brain distribution in a 6-OHDA induced PD mice. These results indicate that magnetic nanoparticle-based hASCs transplantation could be a potential therapeutic strategy in PD.
Project description:The blood-brain barrier (BBB) prevents effective delivery of most therapeutic agents to the brain. Intra-arterial (IA) infusion of hyperosmotic mannitol has been widely used to open the BBB and improve parenchymal targeting, but the extent of BBB disruption has varied widely with therapeutic outcomes often being unpredictable. In this work, we show that real-time MRI can enable fine-tuning of the infusion rate to adjust and predict effective and local brain perfusion in mice, and thereby can be allowed for achieving the targeted and localized BBB opening (BBBO). Both the reproducibility and safety are validated by MRI and histology. The reliable and reproducible BBBO we developed in mice will allow cost-effective studies on the biology of the BBB and drug delivery to the brain. In addition, the IA route for BBBO also permits subsequent IA delivery of a specific drug during the same procedure and obtains high targeting efficiency of the therapeutic agent in the targeted tissue, which has great potential for future clinical translation in neuro-oncology, regenerative medicine and other neurological applications.
Project description:Oxidative stress is an important cause of dopaminergic (DA) neuron apoptosis in Parkinson's disease (PD). Mesenchymal stromal cells (MSCs) possess antioxidative features. In this study, we investigated whether MSCs could reduce oxidative stress and protect DA neurons from apoptosis by intravenous (I.V.) injection in the early stage of a 6-hydroxydopamine (6-OHDA)-induced PD model. MSCs were injected into the tail vein of mice, and behavioral tests, immunofluorescence staining, western blot, and oxidative stress levels were assessed at different time points. After 6-OHDA exposure, DA neuron apoptosis was detected, together with severe oxidative stress in brain and periphery. Compared with the non-transplanted sham controls, motor function in the 6-OHDA-lesioned group after I.V. injection of MSCs was significantly improved, and the levels of DA neuron apoptosis and oxidative stress decreased. The results demonstrate that MSCs can rescue DA neurons from ongoing apoptosis by reducing oxidative stress, and provide insights on developing new therapeutic strategies to offset the degenerative process of PD.
Project description:To determine the influences of exercise on motor deficits and dopaminergic transmission in a hemiparkinson animal model, we measured the effects of exercise on the ambulatory system by estimating spatio-temporal parameters during walking, striatal dopamine (DA) release and reuptake and synaptic plasticity in the corticostriatal pathway after unilateral 6-OHDA lesions. 6-OHDA lesioned hemiparkinsonian rats were exercised on a fixed speed treadmill for 30?minutes per day. Controls received the same lesion but no exercise. Animals were subsequently analyzed for behavior including gait analysis, rotarod performance and apomorphine induced rotation. Subsequently, in vitro striatal dopamine release was analyzed by using FSCV and activity-dependent plasticity in the corticostriatal pathway was measured in each group. Our data indicated that exercise could improve motor walking speed and increase the apomorphine-induced rotation threshold. Exercise also ameliorated spatiotemporal impairments in gait in PD animals. Exercise increased the parameters of synaptic plasticity formation in the corticostriatal pathway of PD animals as well as the dynamics of dopamine transmission in PD animals. Fixed speed treadmill training 30?minutes per day could ameliorate spatial-temporal gait impairment, improve walking speed, dopamine transmission as well as corticostriatal synaptic plasticity in the unilateral 6-OHDA lesioned rat model.