Exercise training has a protective effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model with improved neural and intestinal pathology and modified intestinal flora.

Parkinson's disease (PD) is a common neurodegenerative disease with the exact etiology still unclear, but gut microbial disorders are thought to be related to the initiation and progression of it. Exercise training has a significant effect on the intestinal flora, so to investigate the promotion effect of exercise training on Parkinson's disease, we performed a rotarod walking training (5 times a week at 25 rpm for 20 min for 8 weeks) on a chronic mouse model of Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and observed the locomotor function of mice, function of dopaminergic neurons, intestinal mucosal barrier condition, intestinal inflammation and the structure and composition of intestinal flora. The results showed in these PD mice, exercise training improved their motility, increased the dopamine (DA) content in the striatum, along with promoted the gene expression of tyrosine hydroxylase and brain-derived neurotrophic factor in the striatum, which suggests this exercise training might protect striatal dopaminergic neurons from MPTP damage; the results also showed exercise training promoted recovery from ileal pathology, reduced the gene expression of intestinal inflammatory factors, and significantly altered the composition and structure of the intestinal flora in these mice.

Aerobic exercise improves motor function and striatal MSNs-Erk/MAPK signaling in mice with 6-OHDA-induced Parkinson's disease.

In Parkinson's disease (PD) state, with progressive loss of dopaminergic neurons in the substantia nigra, the striatal dopamine (DA) and glutamate (Glu) levels change, resulting in dysfunction of basal ganglia motor regulation. The PD patient presents motor dysfunction such as resting tremor, bradykinesia, and muscular rigidity. To investigate the mechanism of aerobic exercise to improve PD-related motor dysfunction, in the current study, 6-hydroxydopamine (6-OHDA) was used to induce the PD mice model, and the motor function of PD mice was comprehensively evaluated by open-field test, rotarod test, and gait test. The co-expression of prodynorphin (PDYN) and proenkephalin (PENK) with extracellular signal-regulated kinase (Erk1/2) and phosphorylation Erk1/2 (p-Erk1/2) were detected by double-labeling immunofluorescence. The results showed that a 4-week aerobic exercise intervention could effectively improve the motor dysfunction of PD mice. Moreover, it was found that the expressions of Erk1/2 and p-Erk1/2 in the dorsal striatum (Str) of PD mice were significantly increased, and the number of positive cells co-expressed by Erk1/2, p-Erk1/2, and PENK was significantly higher than PDYN. The above phenomenon was reversed by a 4-week aerobic exercise intervention. Therefore, this study suggests that the mechanism by which aerobic exercise improves PD-related motor dysfunction may be related to that the aerobic exercise intervention alleviates the activity of extracellular signal-regulated kinase/mitogen-activated protein kinases (Erk/MAPK) signaling pathway in striatal medium spiny neurons expressing D2-like receptors (D2-MSNs) of PD mice by regulating the striatal DA and Glu signaling.

Treadmill exercise alleviates neuronal damage by suppressing NLRP3 inflammasome and microglial activation in the MPTP mouse model of Parkinson's disease.

Treadmill exercise has been recognized as an effectively therapeutic strategy for Parkinson's disease (PD). However, its exact molecular mechanism of promoting PD remain unclear. Recently, the NLRP3 inflammasome is considered to play a critical role in the pathogenesis of PD. In this study, we investigated whether NLRP3 inflammasome was involved in treadmill exercise-induced neuroprotection and anti-inflammation effect in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. 8-week-old male mice (C57BL/6 strain) were divided into four groups: Control, MPTP, MPTP + EX and EX. MPTP was intraperitoneally injected into mice to establish chronic PD model. The open-field test and pole test were used to assess motor function. The results showed that treadmill exercise significantly alleviated motor dysfunction and dopaminergic neuron degeneration induced by MPTP. In addition, we also found that treadmill exercise suppressed MPTP-triggered microglia activation and the co-localization of NLRP3+/Iba-1+ cells in the substantia nigra. These effects were associated with suppression NLRP3 inflammasome via down-regulation of TLR4/MyD88/NF-κB pathway. Overall, our study demonstrated that treadmill exercise could effectively alleviates neuronal damage via inhibition of NLRP3 inflammasome and microglial activation in MPTP-induced PD mouse model.

Pesticides and Parkinson's disease: Current and future perspective.

Inappropriate use of pesticides has globally exposed mankind to a number of health hazards. Still their production is rising at the rate of 11 % annually and, has already exceeded more than 5 million tons in 2000 (FAO 2017). Plenty of available data reveals that pesticides exposures through agricultural use and food-preservative residue consumption may lead to neurodegenerative disorders like Parkinson's and Alzheimer's diseases. Parkinson's disease (PD) is a progressive motor impairment and a neurodegenerative disorder, considered as the leading source of motor disability. Pesticides strongly inhibit mitochondrial Complex-I, causing mitochondrial dysfunction and death of dopaminergic neurons in the substantia nigra (SN), thus leading to pathophysiologic implications of PD. Current medical treatment strategies, including pharmacotherapeutics and supportive therapies can only provide symptomatic relief. While complementary and alternative medicines including traditional medicine or acupuncture are considered as beneficial ways of treatment with significant clinical effect. Medically non-responding cases can be treated by surgical means, 'Deep Brain Stimulation'. Cell therapy is also an emerging and promising technology for disease modeling and drug development in PD. Their main aim is to replace and/or support the lost and dying dopaminergic neurons in the SN. Recently I/II clinical phase trial (Japan) have used dopaminergic progenitors generated from induced pluripotent stem (iPS) cells which can unveil a successful cell therapy to treat PD symptoms efficiently. This review focuses on PD caused by pesticides use, current treatment modalities, and ongoing research updates. Since PD is not a cell-autonomous disease rather caused by multiple factors, a combinatorial therapeutic approach may address not only the motor-related symptoms but also non-motor cognitive-behavioral issues.

Human stem cells harboring a suicide gene improve the safety and standardisation of neural transplants in Parkinsonian rats.

Despite advancements in human pluripotent stem cells (hPSCs) differentiation protocols to generate appropriate neuronal progenitors suitable for transplantation in Parkinson's disease, resultant grafts contain low proportions of dopamine neurons. Added to this is the tumorigenic risk associated with the potential presence of incompletely patterned, proliferative cells within grafts. Here, we utilised a hPSC line carrying a FailSafeTM suicide gene (thymidine kinase linked to cyclinD1) to selectively ablate proliferative cells in order to improve safety and purity of neural transplantation in a Parkinsonian model. The engineered FailSafeTM hPSCs demonstrated robust ventral midbrain specification in vitro, capable of forming neural grafts upon transplantation. Activation of the suicide gene within weeks after transplantation, by ganciclovir administration, resulted in significantly smaller grafts without affecting the total yield of dopamine neurons, their capacity to innervate the host brain or reverse motor deficits at six months in a rat Parkinsonian model. Within ganciclovir-treated grafts, other neuronal, glial and non-neural populations (including proliferative cells), were significantly reduced-cell types that may pose adverse or unknown influences on graft and host function. These findings demonstrate the capacity of a suicide gene-based system to improve both the standardisation and safety of hPSC-derived grafts in a rat model of Parkinsonism.

Therapeutic effects of Wharton's jelly-derived Mesenchymal Stromal Cells on behaviors, EEG changes and NGF-1 in rat model of the Parkinson's disease.

Human Wharton's jelly-derived Mesenchymal Stromal Cells (hWJ-MSCs) have shown beneficial effects in improving the dopaminergic cells in the Parkinson's disease (PD). In the present study, the effects of hWJ-MSCs on hyperalgesia, anxiety deficiency and Pallidal local electroencephalogram (EEG) impairment, alone and combined with L-dopa, were examined in a rat model of PD. Adult male Wistar rats were divided into five groups: 1) sham, 2) PD, 3) PD + C (Cell therapy), 4) PD + C+D (Drug), and 5) PD + D. PD was induced by injection of 6-OHDA (16 µg/2 µl into medial forebrain bundle (MFB)). PD + C group received hWJ-MSCs (1 × 106 cells, intravenous (i.v.)) twice post PD induction. PD + C+D groups received hWJ-MSCs combined with L-Dopa/Carbidopa, (10/30 mg/kg, intraperitoneally (i.p.)). PD + D group received L-Dopa/Carbidopa alone. Four months later, analgesia, anxiety-like behaviors, were evaluated and Pallidal local EEG was recorded. Level of insulin-like growth factor 1 (IGF-1) was measured in the striatum and dopaminergic neurons were counted in substantia nigra (SNc). According to data, MFB-lesioned rats showed hyperalgesia in tail flick, anxiety-like symptoms in cognitive tests, impairment of electrical power of pallidal local EEG as field potential, count of dopaminergic neurons in SNc and level of IGF-1 in striatum. These complications restored significantly by MSCs treatment (p < 0.001). Our findings confirm that chronic treatment with hWJ-MSC, alone and in combination with L-Dopa, improved nociception and cognitive deficit in PD rats which may be the result of increasing IGF-1 and protect the viability of dopaminergic neurons.

Early Repetitive Transcranial Magnetic Stimulation Exerts Neuroprotective Effects and Improves Motor Functions in Hemiparkinsonian Rats.

Repetitive transcranial magnetic stimulation (rTMS) is a popular noninvasive technique for modulating motor cortical plasticity and has therapeutic potential for the treatment of Parkinson's disease (PD). However, the therapeutic benefits and related mechanisms of rTMS in PD are still uncertain. Accordingly, preclinical animal research is helpful for enabling translational research to explore an effective therapeutic strategy and for better understanding the underlying mechanisms. Therefore, the current study was designed to identify the therapeutic effects of rTMS on hemiparkinsonian rats. A hemiparkinsonian rat model, induced by unilateral injection of 6-hydroxydopamine (6-OHDA), was applied to evaluate the therapeutic potential of rTMS in motor functions and neuroprotective effect of dopaminergic neurons. Following early and long-term rTMS intervention with an intermittent theta burst stimulation (iTBS) paradigm (starting 24 h post-6-OHDA lesion, 1 session/day, 7 days/week, for a total of 4 weeks) in awake hemiparkinsonian rats, the effects of rTMS on the performance in detailed functional behavioral tests, including video-based gait analysis, the bar test for akinesia, apomorphine-induced rotational analysis, and tests of the degeneration level of dopaminergic neurons, were identified. We found that four weeks of rTMS intervention significantly reduced the aggravation of PD-related symptoms post-6-OHDA lesion. Immunohistochemically, the results showed that tyrosine hydroxylase- (TH-) positive neurons in the substantia nigra pars compacta (SNpc) and fibers in the striatum were significantly preserved in the rTMS treatment group. These findings suggest that early and long-term rTMS with the iTBS paradigm exerts neuroprotective effects and mitigates motor impairments in a hemiparkinsonian rat model. These results further highlight the potential therapeutic effects of rTMS and confirm that long-term rTMS treatment might have clinical relevance and usefulness as an additional treatment approach in individuals with PD.

Forced exercise activates the NrF2 pathway in the striatum and ameliorates motor and behavioral manifestations of Parkinson's disease in rotenone-treated rats.

BACKGROUND: Parkinson's disease (PD) is a common neurodegenerative disorder characterized by progressive loss of nigrostriatal dopaminergic neurons leading to dopamine depletion and problems of movement, emotions, and cognition. While the pathogenesis of PD is not clear, damage of dopaminergic neurons by oxygen-derived free radicals is considered an important contributing mechanism. This study aimed to evaluate the role of treadmill exercise in male Wister rats as a single treatment and as an aid-therapy with L-dopa for rotenone-induced PD. To study the role of the Nrf2- ARE pathway as a mechanism involved in exercise-associated improvement in rotenone-induced PD in rats. METHOD: Animals were divided into 5 groups, (Control, rotenone, rotenone\exercise, rotenone\L-dopa, and rotenone\exercise\L-dopa (combination)groups). After the PD induction, rats in the rotenone\exercise and combination groups were daily treadmill exercised for 4 weeks. RESULTS: Treadmill exercise significantly improved behavioral and motor aspects of rotenone-induced PD. When treadmill exercise was introduced as a single intervention, it amended most behavioral aspects of PD, gait fully corrected, short-term memory, and motor coordination. Where L-dopa corrected locomotor activity and motor coordination but failed to improve short-term memory and only partially corrected the gait of rotenone-treated rats. When treadmill exercise was combined with L-dopa, all features of PD were corrected. It was found that exercise upregulated some of its associative genes to Nrf2 pathways such as TFAM, Nrf2 and NQO.1 mRNA expression. CONCLUSION: This study suggests that forced exercise improved parkinsonian like features by activating the Nrf2 pathway.

Transplanted Wharton's jelly mesenchymal stem cells improve memory and brain hippocampal electrophysiology in rat model of Parkinson's disease.

BACKGROUND: Experimental findings have shown that stem cell transplantation is a therapeutic procedure for Parkinson's disease (PD). In this study, effects of human Wharton's jelly-derived mesenchymal stem cells (hWJ-MSCs), alone and combined with l-dopa, were examined for repairing memory impairment in a rat model of PD. METHODS: Fifty adult male Wistar rats were randomly divided into five groups: 1) sham, 2) PD, 3) PD + C, 4) PD + C+D, and 5) PD + D. PD was induced by 6-OHDA injection (16 µg/2 µl) into medial forebrain bundle (MFB) and was confirmed 14 days later by contralateral rotation using apomorphine injection. The rats received hWJ-MSCs (1 × 106 cells, i.v.) twice on the 14th and 28th days post PD induction. Treated PD rats received hWJ-MSCs alone or combined with l-Dopa and Carbidopa (10/30 mg/kg, i.p.). Four months later, memory, hippocampal long-term potentiation (hLTP), histological changes, and the levels of BDNF and NGF in striatum were evaluated. RESULTS: PD caused both cell loss with small dark stained nuclei in granular zone as well as significant decrement of BDNF and NGF (P < 0.001) in striatum. These pathological alterations were associated with memory and hLTP deficits (P < 0.001 respectively). Treating PD rats with hWJ-MSCs, alone (P < 0.05 and P < 0.001) and combined with l-Dopa (P < 0.001), significantly restored the levels of both of the neurotrophins followed by improving cognition and hLTP (P < 0.001). CONCLUSION: Current findings showed that chronic treatment of PD rats with hWJ-MSCs, alone and in combination with l-Dopa, could restore memory and hLTP by reconstructing dopaminergic neurons and elevating the BDNF and NGF factors.

Potential therapeutic role of fibroblast growth factor 21 in neurodegeneration: Evidence for ameliorating parkinsonism via silent information regulator 2 homolog 1 and implication for gene therapy.

Parkinson's disease (PD) is one of the common complex neurodegenerative diseases and characterized by abnormal metabolic brain networks. Fibroblast growth factor 21 (FGF21), an endocrine hormone that belongs to the fibroblast growth factor superfamily, plays an extensive role in the regulation of metabolism. However, our understandings of the specific function and mechanisms of FGF21 on PD are still quite limited. Here we aimed to elucidate the actions and the underlying mechanisms of FGF21 on dopaminergic neurodegeneration using cellular and animal models of parkinsonism. To investigate the effects of FGF21 on dopaminergic neurodegeneration in vivo and in vitro, 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine models of PD were utilized, and animals were treated with recombinant FGF21 protein or FGF21 gene delivered via an adeno-associated virus. In the present study, systemic and continuous intracerebroventricular recombinant FGF21 protein administration to mice both prevented behavioral deficits, protected dopaminergic neurons against degeneration, and ameliorated α-synuclein pathology in PD models; and in vivo gene delivery of FGF21 improved PD-like symptoms and pathologies suggesting a potential implication of FGF21 in gene therapy for PD. In vitro evidence confirmed FGF21 mediated neuroprotective benefits against PD pathologies. Further, our data suggested that enhanced autophagy was involved in the FGF21 neuroprotection in PD models, and silent information regulator 2 homolog 1 may play a crucial role in molecular mechanisms underlying anti-PD activities of FGF21.

Loss of Collapsin Response Mediator Protein 4 Attenuates 6-Hydroxydopamine-Induced Impairments in a Mouse Model of Parkinson's Disease.

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by impaired motor symptoms induced by the degeneration of dopaminergic neurons of the substantia nigra pars compacta (SNc). Many factors are speculated to operate in the mechanism of PD, including oxidative stress, mitochondrial dysfunction, abnormal protein handling, and PD induced apoptosis. Besides, researchers have recently shown that inflammatory secretions may engage neighboring cells such as astrocytes, which then induce autocrine and paracrine responses that amplify the inflammation, leading to neurodegeneration. In the present study, we analyzed the neuroprotective and anti-inflammatory effects of collapsin response mediator protein 4 (CRMP4) deletion in 6-hydroxydopamine (6-OHDA)-injected male mice, as well as its effects on motor impairments. Our findings indicated that the deletion of CRMP4 could maintain the TH-positive fibers in the striatum and the TH-positive cells in SNc, attenuate the inflammatory responses, and improve motor coordination and rotational behavior. Furthermore, based on our findings at the early time points, we hypothesized that primary differences between the Crmp4+/+ and Crmp4-/- mice may occur in microglia instead of neurons. Although further work should be carried out to clarify the specific role of CRMP4 in the pathogenesis of PD, our findings suggest that it could be a possible target for the treatment of PD.

Purkinje cell misfiring generates high-amplitude action tremors that are corrected by cerebellar deep brain stimulation.

Tremor is currently ranked as the most common movement disorder. The brain regions and neural signals that initiate the debilitating shakiness of different body parts remain unclear. Here, we found that genetically silencing cerebellar Purkinje cell output blocked tremor in mice that were given the tremorgenic drug harmaline. We show in awake behaving mice that the onset of tremor is coincident with rhythmic Purkinje cell firing, which alters the activity of their target cerebellar nuclei cells. We mimic the tremorgenic action of the drug with optogenetics and present evidence that highly patterned Purkinje cell activity drives a powerful tremor in otherwise normal mice. Modulating the altered activity with deep brain stimulation directed to the Purkinje cell output in the cerebellar nuclei reduced tremor in freely moving mice. Together, the data implicate Purkinje cell connectivity as a neural substrate for tremor and a gateway for signals that mediate the disease.

Regular Aerobic Exercise-Alleviated Dysregulation of CAMKIIα Carbonylation to Mitigate Parkinsonism via Homeostasis of Apoptosis With Autophagy.

This study investigated carbonylation of proteins with oxidative modification profiling in the striatum of aging and Parkinson disease (PD) rats, as well as the long-term effects of regular aerobic exercise on the carbonylation process and the damaging effects of PD vs habitual sedentary behavior. Regular aerobic exercise improved the PD rats' rotational behavior, increased tyrosine hydroxylase expression in both the striatum and substantia nigra pars compacta, and decreased α-synuclein expression significantly. Interestingly, apoptotic nuclei and autophagosomes were increased in the aerobic exercise PD rat striatum. Carbonylated protein Ca2+/calmodulin-dependent protein kinase alpha (CAMKIIα) was present in the middle-aged and aged groups but only in the sedentary, not the exercise, PD rat striatum. Notably, CAMKIIα was characterized by a 4-hydroxynonenal adduct. Regular aerobic exercise upregulated CAMKIIα expression level, activated the CAMK signaling pathway, and promoted the expression of autophagy markers Beclin1 and microtubule-associated proteins 1 A/1B light chain 3II. Aberrant carbonylation of CAMKII initiated age-related changes and might be useful as a potential biomarker of PD. Regular aerobic exercise alleviated protein carbonylation modification of CAMKIIα and regulated the CAMK signaling pathway, thereby affecting and regulating the homeostasis of apoptosis and autophagy in the striatum to alleviate the neurodegenerative process of PD lesions.

Alzheimer's Disease and Parkinson's Disease: A Nutritional Toxicology Perspective of the Impact of Oxidative Stress, Mitochondrial Dysfunction, Nutrigenomics and Environmental Chemicals.

Introduction: Alzheimer's disease is primarily a dementia-related disorder from progressive cognitive deterioration and memory impairment, while Parkinson's disease is primarily a movement disorder illness having movement disorder symptoms, bradykinesia (slowness of movements), hypokinesia (reduction of movement amplitude), and akinesia (absence of normal unconscious movements) along with muscle rigidity and tremor at rest. While aging is the main risk factor, epidemiological evidence suggests that the exposure to environmental toxicants, mainly pesticides, metals and solvents could increase the risk of developing neurodegenerative conditions.Oxidative stress in neurodegenerative diseases: Mitochondria function impacts cell respiratory processes, metabolism, energy production, intracellular signaling, free radical production, and apoptosis. In neurodegenerative diseases, mitochondrial dysfunction is associated with a compromised energy production, impaired calcium buffering, activation of proteases and phospholipases, and increased oxidative stress. Oxidative stress induced microglial cells activation, protein aggregation, neuroinflammation and mitochondrial dysfunction lead to neuronal deaths in these disorders.Role of nutrition: Neurodegenerative disease is not curable, but treatment is available to manage the symptoms and slow down the disease progression. The drugs for treating these diseases only reduce the cognitive impairment and behavioral problems, but do not stop the progression of neurodegeneration. Healthy diet, lifestyle improvement and nutraceuticals targeting of oxidative stress, inflammation, abnormal mitochondrial dynamics and the mitochondrial interaction with abnormal disease-related proteins and assessment of impact of environmental contaminants including occupational exposures to pesticides, can be a promising approach in the treatment of neurodegenerative diseases.Conclusion: These innovations can be benchmarked on firm understanding of nutrigenomics and the personalized management of individuals at risk.

Effects of Electroacupuncture on Metabolic Changes in Motor Cortex and Striatum of 6-Hydroxydopamine-Induced Parkinsonian Rats.

OBJECTIVE: To explore the possible underlying mechanism by investigating the effect of electroacupuncture (EA) treatment on the primary motor cortex and striatum in a unilateral 6-hydroxydopamine (6-OHDA) induced rat Parkinson's disease (PD) model. METHODS: Male Sprague-Dawley rats were randomly divided into sham group (n=16), model group (n=14), and EA group (n=14). EA stimulation at Dazhui (GV 14) and Baihui (GV20) was applied to PD rats in the EA group for 4 weeks. Behavioral tests were conducted to evaluate the effectiveness of EA treatment. Metabolites were detected by 7.0 T proton nuclear magnetic resonance. RESULTS: Following 4 weeks of EA treatment in PD model rats, the abnormal behavioral impairment induced by 6-OHDA was alleviated. In monitoring changes in metabolic activity, ratios of myoinositol/creatine (Cr) and N-acetyl aspartate (NAA)/Cr in the primary motor cortex were significantly lower at the injected side than the non-injected side in PD rats (P=0.024 and 0.020). The ratios of glutamate + glutamine (Glx)/Cr and NAA/Cr in the striatum were higher and lower, respectively, at the injected side than the non-injected side (P=0.046 and 0.008). EA treatment restored the balance of metabolic activity in the primary motor cortex and striatum. In addition, the taurine/Cr ratio and Glx/Cr ratio were elevated in the striatum of PD model rats compared to sham-lesioned rats (P=0.026 and 0.000). EA treatment alleviated the excessive glutamatergic transmission by down-regulating the striatal Glx/Cr ratio (P=0.001). The Glx/Cr ratio was negatively correlated with floor plane spontaneous locomotion in PD rats (P=0.027 and P=0.0007). CONCLUSIONS: EA treatment is able to normalize the metabolic balance in the primary motor cortex and striatum of PD rats, which may contribute to its therapeutic effect on motor deficits. The striatal Glx/Cr ratio may serve as a potential indicator of PD and a therapeutic target of EA treatment.

Human autologous iPSC-derived dopaminergic progenitors restore motor function in Parkinson's disease models.

Parkinson's disease (PD) is a neurodegenerative disorder associated with loss of striatal dopamine, secondary to degeneration of midbrain dopamine (mDA) neurons in the substantia nigra, rendering cell transplantation a promising therapeutic strategy. To establish human induced pluripotent stem cell-based (hiPSC-based) autologous cell therapy, we report a platform of core techniques for the production of mDA progenitors as a safe and effective therapeutic product. First, by combining metabolism-regulating microRNAs with reprogramming factors, we developed a method to more efficiently generate clinical-grade iPSCs, as evidenced by genomic integrity and unbiased pluripotent potential. Second, we established a "spotting"-based in vitro differentiation methodology to generate functional and healthy mDA cells in a scalable manner. Third, we developed a chemical method that safely eliminates undifferentiated cells from the final product. Dopaminergic cells thus express high levels of characteristic mDA markers, produce and secrete dopamine, and exhibit electrophysiological features typical of mDA cells. Transplantation of these cells into rodent models of PD robustly restores motor function and reinnervates host brain, while showing no evidence of tumor formation or redistribution of the implanted cells. We propose that this platform is suitable for the successful implementation of human personalized autologous cell therapy for PD.

Focused ultrasound enhanced intranasal delivery of brain derived neurotrophic factor produces neurorestorative effects in a Parkinson's disease mouse model.

Focused ultrasound-enhanced intranasal (IN + FUS) delivery is a noninvasive approach that utilizes the olfactory pathway to administer pharmacological agents directly to the brain, allowing for a more homogenous distribution in targeted locations compared to IN delivery alone. However, whether such a strategy has therapeutic values, especially in neurodegenerative disorders such as Parkinson's disease (PD), remains to be established. Herein, we evaluated whether the expression of tyrosine hydroxylase (TH), the rate limiting enzyme in dopamine catalysis, could be enhanced by IN + FUS delivery of brain-derived neurotrophic factor (BDNF) in a toxin-based PD mouse model. Mice were put on the subacute dosing regimen of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), producing bilateral degeneration of the nigrostriatal pathway consistent with early-stage PD. MPTP mice then received BDNF intranasally followed by multiple unilateral FUS-induced blood-brain barrier (BBB) openings in the left basal ganglia for three consecutive weeks. Subsequently, mice were survived for two months and were evaluated morphologically and behaviorally to determine the integrity of their nigrostriatal dopaminergic pathways. Mice receiving IN + FUS had significantly increased TH immunoreactivity in the treated hemisphere compared to the untreated hemisphere while mice receiving only FUS-induced BBB opening or no treatment at all did not show any differences. Additionally, behavioral changes were only observed in the IN + FUS treated mice, indicating improved motor control function in the treated hemisphere. These findings demonstrate the robustness of the method and potential of IN + FUS for the delivery of bioactive factors for treatment of neurodegenerative disorder.

Immature mDA neurons ameliorate motor deficits in a 6-OHDA Parkinson's disease mouse model and are functional after cryopreservation.

Parkinson's disease is associated with the loss of dopaminergic neurons in the midbrain. Clinical studies investigating replacement of these neurons with in vitro-generated neurons are currently underway. However, this approach has been limited by difficulties in scaling up on-demand production of midbrain dopaminergic (mDA) neurons from pluripotent stem cells. Cryo-preservation may offer a solution, as it allows for banking of quality controlled mDA neurons. In this study, we tested different freezing conditions and found that optimal cryopreservation of immature human mDA neurons at an early differentiation time point was achieved in STEM-CELLBANKER medium using a controlled freezing program.

Striatal overexpression of ß-arrestin2 counteracts L-dopa-induced dyskinesia in 6-hydroxydopamine lesioned Parkinson's disease rats.

Prolonged administration of Levodopa (L-dopa) therapy can generate L-dopa-induced dyskinesia (LID). Accumulating evidence indicates that hyper-activation of the dopamine D1 receptor (D1R) and the cAMP signaling cascade in the medium spiny neurons (MSNs) of the striatum are involved in LID. Previous studies have shown that striatal ß-arrestin2 overexpression significantly reduces LID severity and have indicated that ß-arrestin2 may play a causal role in the dyskinesia sensitization process. L-dopa-induced changes in the expression of signaling molecules and other proteins in the striatum were examined immunohistochemically and by western blot. A rAAV (recombinant adeno-associated virus) vector was used to overexpress and ablate ß-arrestin2. We found that striatal overexpression of AAV-mediated ß-arrestin2 produced less severe AIMs (abnormal involuntary movements) in response to L-dopa, whereas selective deletion of ß-arrestin2 in the striatal neurons dramatically enhanced the severity of dyskinesia induced by L-dopa. Furthermore, no significant improvements in motor behavior (FFT: forelimb functional test) were seen with the inhibition or overexpression of ß-arrestin2. Finally, overexpression of ß-arrestin2 diminished L-dopa-induced D1R and phosphor-DARPP32/ERK levels. Viral deletion of ß-arrestin2 markedly enhanced the key biochemical markers in the direct pathway. We found that increased availability of ß-arrestin2 ameliorated dyskinesia severity with no influence on the anti-Parkinsonian action of L-dopa, suggesting a promising approach for controlling LID in Parkinson's disease. In addition, overexpression of ß-Arrestin2 prevented the development of LID by inhibiting G protein-dependent D1R and phosphor-DARPP32/ERK signaling in dyskinetic rats.

Trabecular meshwork mesenchymal stem cell transplantation improve motor symptoms of parkinsonian rat model.

Stem cell transplantation is a new therapeutic strategy in the treatment of neurodegenerative disorders such as Parkinson's disease (PD). Therefore, in this study, the therapeutic effects of Trabecular Meshwork Mesenchymal Stem Cells (TM-MSCs) transplantation, as a new source of mesenchymal stem cells, were evaluated in the animal model of PD. After the development and confirmation of hemi-parkinsonian rats by administration of 6-hydroxy dopamine (6-OHDA) and apomorphine-induced rotation test, green fluorescent protein (GFP) labeled TM-MSCs (normal and induced cells) were transplanted in the striatum of rats. Next, the rotation test, rotarod test, open field, passive avoidance memory tests and immunohistochemistry for tyrosine hydroxylase (TH) were done. The results showed that the number of turns significantly decreased and the improvement of motor performance was achieved after cell transplantation. However, there was no significant difference in passive avoidance memory of animals documented by shuttle box test. The number of GFP- labeled cells expressing TH significantly is increased compared to the vehicle group. Collectively, it seems that TM-MSCs and induced TM-MSCs cell transplantation have positive effects on some aspects of the animal model of PD. Other studies may reveal the potentially positive aspects of these cells in the laboratory and clinical studies.