Mesenchymal Stem Cell-Derived Extracellular Vesicles as Proposed Therapy in a Rat Model of Cerebral Small Vessel Disease.

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been employed in the past decade as therapeutic agents in various diseases, including central nervous system (CNS) disorders. We currently aimed to use MSC-EVs as potential treatment for cerebral small vessel disease (CSVD), a complex disorder with a variety of manifestations. MSC-EVs were intranasally administrated to salt-sensitive hypertension prone SBH/y rats that were DOCA-salt loaded (SBH/y-DS), which we have previously shown is a model of CSVD. MSC-EVs accumulated within brain lesion sites of SBH/y-DS. An in vitro model of an inflammatory environment in the brain demonstrated anti-inflammatory properties of MSC-EVs. Following in vivo MSC-EV treatment, gene set enrichment analysis (GSEA) of SBH/y-DS cortices revealed downregulation of immune system response-related gene sets. In addition, MSC-EVs downregulated gene sets related to apoptosis, wound healing and coagulation, and upregulated gene sets associated with synaptic signaling and cognition. While no specific gene was markedly altered upon treatment, the synergistic effect of all gene alternations was sufficient to increase animal survival and improve the neurological state of affected SBH/y-DS rats. Our data suggest MSC-EVs act as microenvironment modulators, through various molecular pathways. We conclude that MSC-EVs may serve as beneficial therapeutic measure for multifactorial disorders, such as CSVD.

BDNF overexpression prevents cognitive deficit elicited by adolescent cannabis exposure and host susceptibility interaction.

Cannabis abuse in adolescence is associated with increased risk of psychotic disorders. Δ-9-tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis. Disrupted-In-Schizophrenia-1 (DISC1) protein is a driver for major mental illness by influencing neurodevelopmental processes. Here, utilizing a unique mouse model based on host (DISC1) X environment (THC administration) interaction, we aimed at studying the pathobiological basis through which THC exposure elicits psychiatric manifestations. Wild-Type and dominant-negative-DISC1 (DN-DISC1) mice were injected with THC (10 mg/kg) or vehicle for 10 days during mid-adolescence-equivalent period. Behavioral tests were conducted to assess exploratory activity (open field test, light-dark box test) and cognitive function (novel object recognition test). Electrophysiological effect of THC was evaluated using acute hippocampal slices, and hippocampal cannabinoid receptor type 1 and brain-derived neurotrophic factor (BDNF) protein levels were measured. Our results indicate that THC exposure elicits deficits in exploratory activity and recognition memory, together with reduced short-term synaptic facilitation and loss of BDNF surge in the hippocampus of DN-DISC mice, but not in wild-type mice. Over-expression of BDNF in the hippocampus of THC-treated DN-DISC1 mice prevented the impairment in recognition memory. The results of this study imply that induction of BDNF following adolescence THC exposure may serve as a homeostatic response geared to maintain proper cognitive function against exogenous insult. The BDNF surge in response to THC is perturbed in the presence of mutant DISC1, suggesting DISC1 may be a useful probe to identify biological cascades involved in the neurochemical, electrophysiological, and behavioral effects of cannabis related psychiatric manifestations.

Altered astrocytic response to activation in SOD1(G93A) mice and its implications on amyotrophic lateral sclerosis pathogenesis.

Amyotrophic Lateral Sclerosis (ALS) is a fatal, rapidly progressive, neurodegenerative disease caused by motor neuron degeneration. Despite extensive efforts, the underlying cause of ALS and the path of neurodegeneration remain elusive. Astrocyte activation occurs in response to central nervous system (CNS) insult and is considered a double edged sword in many pathological conditions. We propose that reduced glutamatergic and trophic response of astrocytes to activation may, over time, lead to accumulative CNS damage, thus facilitating neurodegeneration. We found that astrocytes derived from the SOD1(G93A) ALS mouse model exhibit a reduced glutamatergic and trophic response to specific activations compared to their wild-type counterparts. Wild-type astrocytes exhibited a robust response when activated with lipopolysaccharide (LPS), G5 or treated with ceftriaxone in many parameters evaluated. These parameters include increased expression of GLT-1 and GLAST the two major astrocytic glutamate transporters, accompanied by a marked increase in the astrocytic glutamate clearance and up-regulation of neurtrophic factor expression. However, not only do un-treated SOD1(G93A) astrocytes take up glutamate less efficiently, but in response to activation they show no further increase in any of the glutamatergic parameters evaluated. Furthermore, activation of wild-type astrocytes, but not SOD1(G93A) astrocytes, improved their ability to protect the motor neuron cell line NSC-34 from glutamate induced excitotoxicity. Our data indicates that altered astrocyte activation may well be pivotal to the pathogenesis of ALS.

Placental mesenchymal stromal cells induced into neurotrophic factor-producing cells protect neuronal cells from hypoxia and oxidative stress.

BACKGROUND AIMS: Mesenchymal stromal cells (MSC) may be useful in a range of clinical applications. The placenta has been suggested as an abundant, ethically acceptable, less immunogenic and easily accessible source of MSC. The aim of this study was to evaluate the capacity of induced placental MSC to differentiate into neurotrophic factor-producing cells (NTF) and their protective effect on neuronal cells. METHODS: MSC were isolated from placentas and characterized by fluorescence-activated cell sorting (FACS). The cells underwent an induction protocol to differentiate them into NTF. Analysis of the cellular differentiation was done using polymerase chain reactions (PCR), immunocytochemical staining and enzyme-linked immunosorbent assays (ELISA). Conditioned media from placental MSC (PL-MSC) and differentiated MSC (PL-DIFF) were collected and examined for their ability to protect neural cells. RESULTS: The immunocytochemical studies showed that the cells displayed typical MSC membrane markers. The cells differentiated into osteoblasts and adipocytes. PCR and immunohistology staining demonstrated that the induced cells expressed typical astrocytes markers and neurotrophic factors. Vascular endothelial growth factor (VEGF) levels were higher in the conditioned media from PL-DIFF compared with PL-MSC, as indicated by ELISA. Both PL-DIFF and PL-MSC conditioned media markedly protected neural cells from oxidative stress induced by H(2)O(2) and 6-hydroxydopamine. PL-DIFF conditioned medium had a superior effect on neuronal cell survival. Anti-VEGF antibodies (Bevacizumab) reduced the protective effect of the conditioned media from differentiated and undifferentiated MSC. CONCLUSIONS: This study has demonstrated a neuroprotective effect of MSC of placental origin subjected to an induction differentiation protocol. These data offer the prospect of using placenta as a source for stem cell-based therapies.

Chemotherapy Controls Metastasis Through Stimulatory Effects on GRP78 and Its Transcription Factor CREB3L1.

To achieve a cure for metastatic breast cancer, further understanding of molecular drivers of the metastatic cascade is essential. Currently, chemotherapy regimens include doxorubicin and paclitaxel which act in part by inducing the unfolded protein response (UPR). The master regulator of the UPR, glucose regulated protein 78 (GRP78), localizes on the surface of tumor cells and is associated with metastatic disease. Cyclic AMP responsive element binding protein 3-like 1 (CREB3L1), a member of the UPR, is a breast cancer metastasis suppressor that acts on cyclic AMP to promote the expression of target genes including GRP78. The aim of the present study was to evaluate the effects of chemotherapy on CREB3L1 and cell-surface GRP78 expression and its association with the development of breast cancer metastasis. For this purpose, we use breast cancer cells migration in vitro assays and an in vivo metastatic mouse model. The results showed that chemotherapy activated CREB3L1 and enhanced cell-surface GRP78 expression specifically in triple-negative breast cancer cells (TNBC), reducing their migration and metastatic potential. CREB3L1 knockout (KO) in the triple negative MDAMB231 cell line using CRISPR/Cas9 technology led to inhibition of GRP78 expression and abrogation of the CREB3L1 metastatic suppression function. Inoculation of CREB3L1-KO MDAMB231 cells into a mouse metastatic model induced a massive metastatic profile which chemotherapy failed to prevent. These findings elucidate a potential pathway to the development of a novel treatment strategy for metastatic TNBC based on modulating CREB3L1 and cell-surface GRP78 expression by chemotherapy and GRP78-targeted drugs.

Increased RNA editing in maternal immune activation model of neurodevelopmental disease.

The etiology of major neurodevelopmental disorders such as schizophrenia and autism is unclear, with evidence supporting a combination of genetic factors and environmental insults, including viral infection during pregnancy. Here we utilized a mouse model of maternal immune activation (MIA) with the viral mimic PolyI:C infection during early gestation. We investigated the transcriptional changes in the brains of mouse fetuses following MIA during the prenatal period, and evaluated the behavioral and biochemical changes in the adult brain. The results reveal an increase in RNA editing levels and dysregulation in brain development-related gene pathways in the fetal brains of MIA mice. These MIA-induced brain editing changes are not observed in adulthood, although MIA-induced behavioral deficits are observed. Taken together, our findings suggest that MIA induces transient dysregulation of RNA editing at a critical time in brain development.

Myeloperoxidase Deficiency Inhibits Cognitive Decline in the 5XFAD Mouse Model of Alzheimer's Disease.

Myeloperoxidase (MPO) is an enzyme expressed mostly by neutrophils and is a primary mediator of neutrophils oxidative stress response. While a profound body of evidence associates neutrophil-derived MPO in the pathogenesis of Alzheimer's disease (AD), this role has not been assessed in an animal model of AD. Here, we produced hematologic chimerism in the 5XFAD mouse model of AD, with MPO deficient mice, resulting in 5XFAD with hematologic MPO deficiency (5XFAD-MPO KO). Behavioral examinations of 5XFAD-MPO KO showed significant superior performance in spatial learning and memory, associative learning, and anxiety/risk assessment behavior, as compared to 5XFAD mice transplanted with WT cells (5XFAD-WT). Hippocampal immunohistochemical and mRNA expression analyses showed significantly reduced levels of inflammatory mediators in 5XFAD-MPO KO mice with no apparent differences in the numbers of amyloid-ß plaques. In addition, immunoblotting and mRNA analyses showed significantly reduced levels of APOE in 5XFAD-MPO KO. Together, these results indicate a substantial involvement of neutrophil-derived MPO in the pathology of 5XFAD model of AD and suggest MPO as a potential therapeutic target in AD.

Human Muscle Progenitor Cells Overexpressing Neurotrophic Factors Improve Neuronal Regeneration in a Sciatic Nerve Injury Mouse Model.

The peripheral nervous system has an intrinsic ability to regenerate after injury. However, this process is slow, incomplete, and often accompanied by disturbing motor and sensory consequences. Sciatic nerve injury (SNI), which is the most common model for studying peripheral nerve injury, is characterized by damage to both motor and sensory fibers. The main goal of this study is to examine the feasibility of administration of human muscle progenitor cells (hMPCs) overexpressing neurotrophic factor (NTF) genes, known to protect peripheral neurons and enhance axon regeneration and functional recovery, to ameliorate motoric and sensory deficits in SNI mouse model. To this end, hMPCs were isolated from a human muscle biopsy, and manipulated to ectopically express brain-derived neurotrophic factor (BDNF), glial-cell-line-derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF-1). These hMPC-NTF were transplanted into the gastrocnemius muscle of mice after SNI, and motor and sensory functions of the mice were assessed using the CatWalk XT system and the hot plate test. ELISA analysis showed that genetically manipulated hMPC-NTF express significant amounts of BDNF, GDNF, VEGF, or IGF-1. Transplantation of 3 × 106 hMPC-NTF was shown to improve motor function and gait pattern in mice following SNI surgery, as indicated by the CatWalk XT system 7 days post-surgery. Moreover, using the hot-plate test, performed 6 days after surgery, the treated mice showed less sensory deficits, indicating a palliative effect of the treatment. ELISA analysis following transplantation demonstrated increased NTF expression levels in the gastrocnemius muscle of the treated mice, reinforcing the hypothesis that the observed positive effect was due to the transplantation of the genetically manipulated hMPC-NTF. These results show that genetically modified hMPC can alleviate both motoric and sensory deficits of SNI. The use of hMPC-NTF demonstrates the feasibility of a treatment paradigm, which may lead to rapid, high-quality healing of damaged peripheral nerves due to administration of hMPC. Our approach suggests a possible clinical application for the treatment of peripheral nerve injury.

The Role of MAPK's Signaling in Mediating ApoE4-Driven Pathology In Vivo.

BACKGROUND: Alzheimer's Disease (AD) is associated with impairments in key brain Mitogen- Activated Protein Kinase (MAPK) signaling cascades including the p38, c-Jun N-terminal kinase (JNK), ERK and Akt pathways. Apolipoprotein E4 (ApoE4) is the most prevalent genetic risk factor of AD. OBJECTIVES: To investigate the extent to which the MAPK signaling pathway plays a role in mediating the pathological effects of apoE4 and can be reversed by experimental manipulations. METHODS: Measurements of total level and activation of MAPK signaling pathway factors, obtained utilizing immunoblot assay of hippocampal tissues from naïve and viral-treated apoE3 and apoE4 targeted replacement mice. RESULTS: ApoE4 mice showed robust activation of the stress related p38 and JNK pathways and a corresponding decrease in Akt activity, which is coupled to activation of GSK3ß and tau hyperphosphorylation. There was no effect on the ERK pathway. We have previously shown that the apoE4- related pathology, namely; accumulation of Aß, hyper-phosphorylated tau, synaptic impairments and decreased VEGF levels can be reversed by up-regulation of VEGF level utilizing a VEGF-expressing adeno-associated virus. Utilizing this approach, we assessed the extent to which the AD-hallmark and synaptic pathologies of apoE4 are related to the corresponding MAPK signaling effects. This revealed that the reversal of the apoE4-driven pathology via VEGF treatment was associated with a reversal of the p38 and Akt related effects. CONCLUSION: Taken together, these results suggest that the p38 and Akt pathways play a role in mediating the AD-related pathological effects of apoE4 in the hippocampus.

Induction of human mesenchymal stem cells into dopamine-producing cells with different differentiation protocols.

Several reports have shown that human mesenchymal stem cells (MSCs) are capable of differentiating outside the mesenchymal lineage. We sought to induce MSCs to differentiate into dopamine-producing cells for potential use in autologous transplantation in patients with Parkinson's disease (PD). Following cell culture with various combinations of differentiation agents under serum-free defined conditions, different levels of up-regulation were observed in the protein expression of tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. Further analysis of selected differentiation protocols revealed that the induced cells displayed a neuron-like morphology and expressed markers suggesting neuronal differentiation. In addition, there was an increase in Nurr 1, the dopaminergic transcription factor gene, concomitant with a decrease gamma-aminobutyric acid (GABA)ergic marker expression, suggesting a specific dopaminergic direction. Moreover, the induced cells secreted dopamine in response to depolarization. These results demonstrate the great therapeutic potential of human MSCs in PD.

DJ-1 based peptide, ND-13, promote functional recovery in mouse model of focal ischemic injury.

Stroke is a leading cause of death worldwide and inflicts serious long-term damage and disability. The vasoconstrictor Endothelin-1, presenting long-term neurological deficits associated with excitotoxicity and oxidative stress is being increasingly used to induce focal ischemic injury as a model of stroke. A DJ-1 based peptide named ND-13 was shown to protect against glutamate toxicity, neurotoxic insults and oxidative stress in various animal models. Here we focus on the benefits of treatment with ND-13 on the functional outcome of focal ischemic injury. Wild type C57BL/6 mice treated with ND-13, after ischemic induction in this model, showed significant improvement in motor function, including improved body balance and motor coordination, and decreased motor asymmetry. We found that DJ-1 knockout mice are more sensitive to Endothelin-1 ischemic insult than wild type mice, contributing thereby additional evidence to the widely reported relevance of DJ-1 in neuroprotection. Furthermore, treatment of DJ-1 knockout mice with ND-13, following Endothelin-1 induced ischemia, resulted in significant improvement in motor functions, suggesting that ND-13 provides compensation for DJ-1 deficits. These preliminary results demonstrate a possible basis for clinical application of the ND-13 peptide to enhance neuroprotection in stroke patients.

Combined Gene Therapy to Reduce the Neuronal Damage in the Mouse Model of Focal Ischemic Injury.

Research into stroke is driven by frustration over the limited available therapeutics. Targeting a single aspect of this multifactorial disease contributes to the therapeutic boundaries. To overcome this, we devised a novel multifactorial-cocktail treatment, using lentiviruses encoding excitatory amino acid transporter 2 (EAAT2(, glutamate dehydrogenase 2 (GDH2), and nuclear factor E2-related factor 2 (Nrf2) genes, that acts synergistically to address the effected excito-oxidative axis. Here, we used the vasoconstrictor endothelin-1 (ET-1) to induce focal ischemic injury in mice by direct injection into the striatum. Mice treated with the mixture of these three genes show significant improvement in body balance, motor coordination, and decreased motor asymmetry compared to each gene separately. These results demonstrate that overexpression of the combined EAAT2, GDH2, and NRF2 genes can provide neuroprotection after ischemic injury.

Computer-Aided Design and Synthesis of 1-{4-[(3,4-Dihydroxybenzylidene)amino]phenyl}-5-oxopyrrolidine-3-carboxylic Acid as an Nrf2 Enhancer.

The design and synthesis of a novel nuclear factor erythroid 2-related factor 2 (Nrf2) enhancer is reported. Using a structure-based virtual screening approach, several commercially available compounds were identified as having high probability to interact with the Nrf2-binding pocket in the Kelch-like ECH-associated protein 1 (Keap1). Keap1 is an adaptor protein that recruits Nrf2 to a cullin-3-dependent ubiquitin ligase complex. The identified compounds were tested against rat pheochromocytoma PC-12 cells for their cytoprotective activity, and one compound (SKT359126) demonstrated an Nrf2-mediated cell-protective effect. Based on the structure of SKT359126, 23 novel derivatives were synthesized and evaluated. Of the screened derivatives, 1-{4-[(3,4-dihydroxybenzylidene)amino]phenyl}-5-oxopyrrolidine-3-carboxylic acid demonstrated better activity than the parent molecules in activating the Nrf2 transduction pathway in a dose- and time-dependent manner. This compound represents a promising starting point for the development of therapeutics for the treatment of oxidative-stress-related diseases.

Computer-Aided Design and Synthesis of 1-{4-[(3,4-Dihydroxybenzylidene)amino]phenyl}-5-oxopyrrolidine-3-carboxylic Acid as an Nrf2 Enhancer.

Invited for this month's cover is Prof. Arie Gruzman (Bar-Ilan University) and collaborators who have developed an Nrf2 enhancer. This compound activated the Nrf2 transduction pathway and because of this the translation of dozens of antioxidant cytoprotective proteins in a dose- and time-dependent manner and protected PC-12 cells against oxidative stress. Considering the imbalance between production and elimination of oxidative species involved in the pathophysiology of many human diseases, this compound is a promising starting point for the development of novel therapeutics for the treatment of oxidative-stress-related diseases. Read the full text of the article at 10.1002/cplu.201700539.

Dopaminergic differentiation of human mesenchymal stem cells--utilization of bioassay for tyrosine hydroxylase expression.

Parkinson's disease (PD) is a neurodegenerative disorder, caused by a selective loss of dopaminergic neurons in the substantia nigra. In PD, the best therapeutic modalities cannot halt the degeneration. The selective hallmark pathology and the lack of effective treatment make PD an appropriate candidate for cell replacement therapy. Adult autologous bone-marrow-derived mesenchymal stem cells (MSCs) have been investigated as candidates for cell replacement strategies. Several laboratories, including ours, have induced MSCs into neuron-like cells demonstrating a variety of neuronal markers including dopaminergic characteristics, such as the expression of tyrosine hydroxylase (TH). This project aimed to induce MSCs into mature dopamine secreting cells and to generate a bioassay to evaluate the induction. For that purpose, we created a reporter vector containing a promoter of TH, the rate-limiting enzyme in the dopamine synthesis and red fluorescent protein DsRed2. Transfection of human neuroblastoma, dopamine synthesizing, SH-SY5Y cells confirmed the reliability of the constructed reporter plasmid. Following dopaminergic differentiation of the transfected human MSCs cells, TH expressing cells were identified and quantified using flow cytometry. Further study revealed that not only did the differentiated cells activate TH promoter but they also expressed TH protein and secreted dopamine. The reported results indicate that MSCs may be primed in vitro towards a dopaminergic fate offering the promise of innovative therapy for currently incurable human disorders, including PD.

A Multifunctional Biocompatible Drug Candidate is Highly Effective in Delaying Pathological Signs of Alzheimer's Disease in 5XFAD Mice.

BACKGROUND: Metal-ion-chelation was suggested to prevent zinc and copper ions-induced amyloid-ß (Aß) aggregation and oxidative stress, both implicated in the pathophysiology of Alzheimer's disease (AD). In a quest for biocompatible metal-ion chelators potentially useful for AD therapy, we previously tested a series of nucleoside 5'-phosphorothioate derivatives as agents for decomposition of Cu(I)/Cu(II)/Zn(II)-Aß-aggregates, and as inhibitors of OH radicals formation in Cu(I) or Fe(II) /H2O2 solution. Specifically, in our recent study we have identified 2-SMe-ADP(α-S), designated as SAS, as a most promising neuroprotectant. OBJECTIVE: To further explore SAS ability to protect the brain from Aß toxicity both in vitro and in vivo. METHODS: We evaluated SAS ability to decompose or inhibit the formation of Aß42-M(II) aggregates, and rescue primary neurons and astrocytes from Aß42 toxicity. Furthermore, we aimed at exploring the therapeutic effect of SAS on behavioral and cognitive deficits in the 5XFAD mouse model of AD. RESULTS: We found that SAS can rescue primary culture of neurons and astrocytes from Aß42 toxicity and to inhibit the formation and dissolve Aß42-Zn(II)/Cu(II) aggregates. Furthermore, we show that SAS treatment can prevent behavioral disinhibition and ameliorate spatial working memory deficits in 5XFAD mice. Notably, the mice were treated at the age of 2 months, before the onset of AD symptoms, for a duration of 2 months, while the effect was demonstrated at the age of 6 months. CONCLUSION: Our results indicate that SAS has the potential to delay progression of core pathological characteristics of AD in the 5XFAD mouse model.

Human mesenchymal stem cells express neural genes, suggesting a neural predisposition.

Because of their unique attributes of plasticity and accessibility, bone marrow-derived mesenchymal stem cells (MSCs) may find use for therapy of neurodegenerative disorders. Our previous studies of adult human MSCs demonstrated that these cells express an extensive assortment of neural genes at a low but clearly detectable level. Here, we report expression of 12 neural genes, 8 genes related to the neuro-dopaminergic system, and 11 transcription factors with neural significance by human MSCs. Our results suggest that, as opposed to cells that do not express neural genes, human MSCs are predisposed to differentiate to neuronal and glial lineages, given the proper conditions. Our findings add a new dimension in which to view adult stem cell plasticity, and may explain the relative ease with which MSCs, transplanted into the central nervous system (CNS) differentiate to a variety of functional neural cell types. Our results further promote the possibility that adult human MSCs are promising candidates for cell-based therapy of neurodegenerative diseases.

Multifactorial Gene Therapy Enhancing the Glutamate Uptake System and Reducing Oxidative Stress Delays Symptom Onset and Prolongs Survival in the SOD1-G93A ALS Mouse Model.

The 150-year-long search for treatments of amyotrophic lateral sclerosis (ALS) is still fueled by frustration over the shortcomings of available therapeutics. Contributing to the therapeutic limitations might be the targeting of a single aspect of this multifactorial-multisystemic disease. In an attempt to overcome this, we devised a novel multifactorial-cocktail treatment, using lentiviruses encoding: EAAT2, GDH2, and NRF2, that act synergistically to address the band and width of the effected excito-oxidative axis, reducing extracellular-glutamate and glutamate availability while improving the metabolic state and the anti-oxidant response. This strategy yielded particularly impressive results, as all three genes together but not separately prolonged survival in ALS mice by an average of 19-22 days. This was accompanied by improvement in every parameter evaluated, including body-weight loss, reflex score, neurologic score, and motor performance. We hope to provide a novel strategy to slow down disease progression and alleviate symptoms of patients suffering from ALS.

Neuroprotective Effect of a DJ-1 Based Peptide in a Toxin Induced Mouse Model of Multiple System Atrophy.

Multiple System Atrophy (MSA) is a sporadic neurodegenerative disorder characterized by parkinsonism, cerebellar ataxia and dysautonomia, in various combinations. In MSA with parkinsonism (MSA-P), the degeneration is mainly restricted to the substantia nigra pars compacta and putamen. Studies have identified alterations in DJ-1 (PARK7), a key component of the anti-oxidative stress response, in Parkinson's disease (PD) and MSA patients. Previously we have shown that a short DJ-1-based peptide named ND-13, protected cultured cells against neurotoxic insults and improved behavioral outcome in animal models of Parkinson's disease (PD). In this study, we used the 3-Nitropropionic acid (3-NP)-induced mouse model of MSA and treated the animals with ND-13 in order to evaluate its therapeutic effects. Our results show that ND-13 protects cultured cells against oxidative stress generated by the mitochondrial inhibitor, 3-NP. Moreover, we show that ND-13 attenuates nigrostriatal degeneration and improves performance in motor-related behavioral tasks in 3-NP-treated mice. Our findings suggest a rationale for using ND-13 as a promising therapeutic approach for treatment of MSA.

Reversal of ApoE4-Driven Brain Pathology by Vascular Endothelial Growth Factor Treatment.

Apolipoprotein E4 (ApoE4), the most prevalent genetic risk factor for Alzheimer's disease (AD), is associated with increased neurodegeneration and vascular impairments. Vascular endothelial growth factor (VEGF), originally described as a key angiogenic factor, has recently been shown to play a crucial role in the nervous system. The objective of this research is to examine the role of VEGF in mediating the apoE4-driven pathologies. We show that hippocampal VEGF levels are lower in apoE4 targeted replacement mice compared to the corresponding apoE3 mice. This effect was accompanied by a specific decrease in both VEGF receptor-2 and HIF1-α. We next set to examine whether upregulation of VEGF can reverse apoE4-driven pathologies, namely the accumulation of hyperphosphorylated tau (AT8) and Aß42, and reduced levels of the pre-synaptic marker, VGluT1, and of the ApoE receptor, ApoER2. This was first performed utilizing intra-hippocampal injection of VEGF-expressing-lentivirus (LV-VEGF). This revealed that LV-VEGF treatment reversed the apoE4-driven cognitive deficits and synaptic pathologies. The levels of Aß42 and AT8, however, were increased in apoE3 mice, masking any potential effects of this treatment on the apoE4 mice. Follow-up experiments utilizing VEGF-expressing adeno-associated-virus (AAV-VEGF), which expresses VEGF specifically under the GFAP astrocytic promoter, prevented this effects on apoE3 mice, and reversed the apoE4-related increase in Aß42 and AT8. Taken together, these results suggest that apoE4-driven pathologies are mediated by a VEGF-dependent pathway, resulting in cognitive impairments and brain pathology. These animal model findings suggest that the VEGF system is a promising target for the treatment of apoE4 carriers in AD.