DPP-4 inhibitors sitagliptin and PF-00734,200 mitigate dopaminergic neurodegeneration, neuroinflammation and behavioral impairment in the rat 6-OHDA model of Parkinson's disease.

Epidemiological studies report an elevated risk of Parkinson's disease (PD) in patients with type 2 diabetes mellitus (T2DM) that is mitigated in those prescribed dipeptidyl peptidase 4 (DPP-4) inhibitors. With an objective to characterize clinically translatable doses of DPP-4 inhibitors (gliptins) in a well-characterized PD rodent model, sitagliptin, PF-00734,200 or vehicle were orally administered to rats initiated either 7-days before or 7-days after unilateral medial forebrain bundle 6-hydroxydopamine (6-OHDA) lesioning. Measures of dopaminergic cell viability, dopamine content, neuroinflammation and neurogenesis were evaluated thereafter in ipsi- and contralateral brain. Plasma and brain incretin and DPP-4 activity levels were quantified. Furthermore, brain incretin receptor levels were age-dependently evaluated in rodents, in 6-OHDA challenged animals and human subjects with/without PD. Cellular studies evaluated neurotrophic/neuroprotective actions of combined incretin administration. Pre-treatment with oral sitagliptin or PF-00734,200 reduced methamphetamine (meth)-induced rotation post-lesioning and dopaminergic degeneration in lesioned substantia nigra pars compacta (SNc) and striatum. Direct intracerebroventricular gliptin administration lacked neuroprotective actions, indicating that systemic incretin-mediated mechanisms underpin gliptin-induced favorable brain effects. Post-treatment with a threefold higher oral gliptin dose, likewise, mitigated meth-induced rotation, dopaminergic neurodegeneration and neuroinflammation, and augmented neurogenesis. These gliptin-induced actions associated with 70-80% plasma and 20-30% brain DPP-4 inhibition, and elevated plasma and brain incretin levels. Brain incretin receptor protein levels were age-dependently maintained in rodents, preserved in rats challenged with 6-OHDA, and in humans with PD. Combined GLP-1 and GIP receptor activation in neuronal cultures resulted in neurotrophic/neuroprotective actions superior to single agonists alone. In conclusion, these studies support further evaluation of the repurposing of clinically approved gliptins as a treatment strategy for PD.

Sitagliptin elevates plasma and CSF incretin levels following oral administration to nonhuman primates: relevance for neurodegenerative disorders.

The endogenous incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) possess neurotrophic, neuroprotective, and anti-neuroinflammatory actions. The dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin reduces degradation of endogenous GLP-1 and GIP, and, thereby, extends the circulation of these protective peptides. The current nonhuman primate (NHP) study evaluates whether human translational sitagliptin doses can elevate systemic and central nervous system (CNS) levels of GLP-1/GIP in naive, non-lesioned NHPs, in line with our prior rodent studies that demonstrated sitagliptin efficacy in preclinical models of Parkinson's disease (PD). PD is an age-associated neurodegenerative disorder whose current treatment is inadequate. Repositioning of the well-tolerated and efficacious diabetes drug sitagliptin provides a rapid approach to add to the therapeutic armamentarium for PD. The pharmacokinetics and pharmacodynamics of 3 oral sitagliptin doses (5, 20, and 100 mg/kg), equivalent to the routine clinical dose, a tolerated higher clinical dose and a maximal dose in monkey, were evaluated. Peak plasma sitagliptin levels were aligned both with prior reports in humans administered equivalent doses and with those in rodents demonstrating reduction of PD associated neurodegeneration. Although CNS uptake of sitagliptin was low (cerebrospinal fluid (CSF)/plasma ratio 0.01), both plasma and CSF concentrations of GLP-1/GIP were elevated in line with efficacy in prior rodent PD studies. Additional cellular studies evaluating human SH-SY5Y and primary rat ventral mesencephalic cultures challenged with 6-hydroxydopamine, established cellular models of PD, demonstrated that joint treatment with GLP-1 + GIP mitigated cell death, particularly when combined with DPP-4 inhibition to maintain incretin levels. In conclusion, this study provides a supportive translational step towards the clinical evaluation of sitagliptin in PD and other neurodegenerative disorders for which aging, similarly, is the greatest risk factor.

Peptide immunization against the C-terminal of alpha-synuclein reduces locomotor activity in mice overexpressing alpha-synuclein.

Abnormal accumulation of alpha-synuclein (αSyn) in the remaining nigra dopaminergic neurons is a common neuropathological feature found in patients with Parkinson's disease (PD). Antibody-based immunotherapy has been considered a potential approach for PD treatment. This study aims to investigate the effectiveness of active immunization against αSyn in a mouse model of PD. Adult mice were immunized with or without a synthetic peptide containing the C-terminal residues of human αSyn and activation epitopes, followed by an intranigral injection of adeno-associated virus vectors for overexpressing human αSyn. Upon the peptide injection, αSyn-specific antibodies were raised, accompanied by degeneration of dopaminergic neurons and motor deficits. Furthermore, the induction of neuroinflammation was postulated by the elevation of astroglial and microglial markers in the immunized mice. Instead of lessening αSyn toxicity, this peptide vaccine caused an increase in the pathogenic species of αSyn. Our data demonstrated the potential adverse effects of active immunization to raise antibodies against the C-terminal fragment of αSyn. This drawback highlights the need for further investigation to weigh the pros and cons of immunotherapy in PD. Applying the αSyn C-terminal peptide vaccine for PD treatment should be cautiously exercised. This study provides valuable insights into the intricate interplay among immune intervention, αSyn accumulation, and neurodegeneration.

Prosaposin PS18 reduces dopaminergic neurodegeneration in a 6-hydroxydopamine rat model of Parkinson's disease.

Saposin and its precursor prosaposin are endogenous proteins with neurotrophic and anti-apoptotic properties. Prosaposin or its analog prosaposin-derived 18-mer peptide (PS18) reduced neuronal damage in hippocampus and apoptosis in stroke brain. Its role in Parkinson's disease (PD) has not been well characterized. This study aimed to examine the physiological role of PS18 in 6-hydroxydopamine (6-OHDA) cellular and animal models of PD. We found that PS18 significantly antagonized 6-OHDA -mediated dopaminergic neuronal loss and TUNEL in rat primary dopaminergic neuronal culture. In SH-SY5Y cells overexpressing the secreted ER calcium-monitoring proteins, we found that PS18 significantly reduced thapsigargin and 6-OHDA-mediated ER stress. The expression of prosaposin and the protective effect of PS18 were next examined in hemiparkinsonian rats. 6-OHDA was unilaterally administered to striatum. The expression of prosaposin was transiently upregulated in striatum on D3 (day 3) after lesioning and returned below the basal level on D29. The 6-OHDA-lesioned rats developed bradykinesia and an increase in methamphetamine-mediated rotation, which was antagonized by PS18. Brain tissues were collected for Western blot, immunohistochemistry, and qRTPCR analysis. Tyrosine hydroxylase immunoreactivity was significantly reduced while the expressions of PERK, ATF6, CHOP, and BiP were upregulated in the lesioned nigra; these responses were significantly antagonized by PS18. Taken together, our data support that PS18 is neuroprotective in cellular and animal models of PD. The mechanisms of protection may involve anti-ER stress.

Herbal formula PM012 induces neuroprotection in stroke brain.

Stroke is a major cause of long-term disability world-wide. Limited pharmacological therapy has been used in stroke patients. Previous studies indicated that herb formula PM012 is neuroprotective against neurotoxin trimethyltin in rat brain, and improved learning and memory in animal models of Alzheimer's disease. Its action in stroke has not been reported. This study aims to determine PM012-mediated neural protection in cellular and animal models of stroke. Glutamate-mediated neuronal loss and apoptosis were examined in rat primary cortical neuronal cultures. Cultured cells were overexpressed with a Ca++ probe (gCaMP5) by AAV1 and were used to examine Ca++ influx (Ca++i). Adult rats received PM012 before transient middle cerebral artery occlusion (MCAo). Brain tissues were collected for infarction and qRTPCR analysis. In rat primary cortical neuronal cultures, PM012 significantly antagonized glutamate-mediated TUNEL and neuronal loss, as well as NMDA-mediated Ca++i. PM012 significantly reduced brain infarction and improved locomotor activity in stroke rats. PM012 attenuated the expression of IBA1, IL6, and CD86, while upregulated CD206 in the infarcted cortex. ATF6, Bip, CHOP, IRE1, and PERK were significantly down-regulated by PM012. Using HPLC, two potential bioactive molecules, paeoniflorin and 5-hydroxymethylfurfural, were identified in the PM012 extract. Taken together, our data suggest that PM012 is neuroprotective against stroke. The mechanisms of action involve inhibition of Ca++i, inflammation, and apoptosis.

Alleviation of Methamphetamine Sensitization by Partially Lesioning Dopaminergic Terminals with 6-Hydroxydopamine in Nucleus Accumbens.

Amphetamine-type stimulants have become important and popular abused drugs worldwide. Methamphetamine (Meth) sensitization, characterized by a progressive increase in behavioral responses after repeated administration, has been reported in rodents and patients. This behavioral effect has been used as a laboratory model to study drug addiction and schizophrenia. The mesolimbic dopaminergic pathway plays a significant role in the development of Meth behavioral sensitization. Previous studies have reported that the ablation of nucleus accumbens (NAc) by electrolytic or thermal lesioning attenuates addictive behavior to opioids in animals. However, these studies were only conducted in opioid addictive rodents. Furthermore, these ablation procedures also damaged the non-dopaminergic neurons and fibers passing through the NAc. The purpose of this study was to examine the therapeutic effect of NAc lesioning by a selective dopaminergic toxin in Meth-sensitized animals. Adult mice received repeated administration of Meth for 7 days. Open-field locomotor activity and stereotype behavior were significantly increased after Meth treatment, suggesting behavior sensitization. A partial lesion of dopaminergic terminals was made through stereotaxic administration of dopaminergic toxin 6-hydroxydopamine (6-OHDA) to the NAc in the Meth -sensitized mice. Meth behavioral sensitization was significantly antagonized after the lesioning. Brain tissue was collected for qRT-PCR analysis. Repeated administration of Meth increased the expression of tyrosine hydroxylase (TH), BDNF, and Shati, a marker for Meth sensitization, in the NAc. Treatment with 6-OHDA significantly antagonized the upregulation of TH and Shati. Taken together, these data suggest that local administration of 6-OHDA mitigated Meth sensitization in chronic Meth-treated animals. Our data support a new surgical treatment strategy for Meth abuse.

Human Milk Oligosaccharide 2'-Fucosyllactose Induces Neuroprotection from Intracerebral Hemorrhage Stroke.

Intracerebral hemorrhage (ICH) occurs when brain blood vessels rupture, causing inflammation and cell death. 2-Fucosyllactose (2FL), a human milk oligosaccharide, has potent antiapoptotic and anti-inflammatory effects. The purpose of this study was to examine the protective effect of 2FL in cellular and rodent models of ICH. Hemin was added to a primary rat cortical neuronal and BV2 microglia coculture to simulate ICH in vitro. IBA1 and MAP2 immunoreactivities were used to determine inflammation and neuronal survival. Hemin significantly increased IBA1, while it reduced MAP2 immunoreactivity. 2FL significantly antagonized both responses. The protective effect of 2FL was next examined in a rat ICH model. Intracerebral administration of type VII collagenase reduced open-field locomotor activity. Early post-treatment with 2FL significantly improved locomotor activity. Brain tissues were collected for immunohistochemistry and qRT-PCR analysis. 2FL reduced IBA1 and CD4 immunoreactivity in the lesioned striatum. 2FL downregulated the expression of ER stress markers (PERK and CHOP), while it upregulated M2 macrophage markers (CD206 and TGFß) in the lesioned brain. Taken together, our data support that 2FL has a neuroprotective effect against ICH through the inhibition of neuroinflammation and ER stress. 2FL may have clinical implications for the treatment of ICH.

Administration of AAV-Alpha Synuclein NAC Antibody Improves Locomotor Behavior in Rats Overexpressing Alpha Synuclein.

Accumulation of α-Synuclein (αSyn) in nigral dopaminergic neurons is commonly seen in patients with Parkinson's disease (PD). We recently reported that transduction of intracellular single-chain intrabody targeting the 53-87 amino acid residues of human αSyn by recombinant adeno associated viral vector (AAV-NAC32) downregulated αSyn protein in SH-SY5Y cells and rat brain. This study characterizes the behavioral phenotype and dopaminergic protection in animals receiving AAV-NAC32. Our results show that adult DAT-Cre rats selectively overexpress αSyn in nigra dopaminergic neurons after local administration of AAV-DIO-αSyn. These animals develop PD-like phenotype, including bradykinesia and loss of tyrosine hydroxylase (TH) immunoreactivity in substantia nigra pars compacta dorsal tier (SNcd). An injection of AAV-NAC32 to nigra produces a selective antibody against αSyn and normalizes the behavior. AAV-NAC32 significantly increases TH, while reduces αSyn immunoreactivity in SNcd. Altogether, our data suggest that an AAV-mediated gene transfer of NAC32 antibody effectively antagonizes αSyn-mediated dopaminergic degeneration in nigra, which may be a promising therapeutic candidate for synucleinopathy or PD.

Naltrexone is neuroprotective against traumatic brain injury in mu opioid receptor knockout mice.

AIMS: Naltrexone is a mu opioid receptor (MOR) antagonist used to treat drug dependence in patients. Previous reports indicated that MOR antagonists reduced neurodegeneration and inflammation after brain injury. The purpose of this study was to evaluate the neuroprotective effect of naltrexone in cell culture and a mouse model of traumatic brain injury (TBI). METHODS: The neuroprotective effect of naltrexone was examined in primary cortical neurons co-cultured with BV2 microglia. Controlled cortical impact (CCI) was delivered to the left cerebral cortex of adult male MOR wild-type (WT) and knockout (KO) mice. Naltrexone was given daily for 4 days, starting from day 2 after lesioning. Locomotor activity was evaluated on day 5 after the CCI. Brain tissues were collected for immunostaining, Western, and qPCR analysis. RESULTS: Glutamate reduced MAP2 immunoreactivity (-ir), while increased IBA1-ir in neuron/BV2 co-culture; both responses were antagonized by naltrexone. TBI significantly reduced locomotor activity and increased the expression of IBA1, iNOS, and CD4 in the lesioned cortex. Naltrexone significantly and equally antagonized the motor deficits and expression of IBA1 and iNOS in WT and KO mice. TBI-mediated CD4 protein production was attenuated by naltrexone in WT mice, but not in KO mice. CONCLUSION: Naltrexone reduced TBI-mediated neurodegeneration and inflammation in MOR WT and KO mice. The protective effect of naltrexone involves non-MOR and MOR mechanisms.

Protective Effect of CXCR4 Antagonist CX807 in a Rat Model of Hemorrhagic Stroke.

Intracerebral hemorrhage (ICH) is a major cause of stroke, with high mortality and morbidity. There is no effective pharmacological therapy for ICH. Previous studies have indicated that CXCR4 antagonists reduced microglia activation, attenuated infiltration of T cells, and improved functional recovery in ischemic stroke animals. The interaction of CXCR4 antagonists and ICH has not been characterized. The purpose of this study is to examine the neuroprotective action of a novel CXCR4 antagonist CX807 against ICH. In primary cortical neuronal and BV2 microglia co-culture, CX807 reduced glutamate-mediated neuronal loss and microglia activation. Adult rats were locally administered with collagenase VII to induce ICH. CX807 was given systemically after the ICH. Early post-treatment with CX807 improved locomotor activity in ICH rats. Brain tissues were collected for qRTPCR and histological staining. ICH upregulated the expression of CXCR4, CD8, TNFα, IL6, and TLR4. The immunoreactivity of IBA1 and CD8, as well as TUNEL labeling, were enhanced in the perilesioned area. CX807 significantly mitigated these responses. In conclusion, our data suggest that CX807 is neuroprotective and anti-inflammatory against ICH. CX807 may have clinical implications for the treatment of hemorrhagic stroke.

PT320, Sustained-Release Exendin-4, Mitigates L-DOPA-Induced Dyskinesia in a Rat 6-Hydroxydopamine Model of Parkinson's Disease.

BACKGROUND: We previously demonstrated that subcutaneous administration of PT320, a sustained-release (SR) form of exendin-4, resulted in the long-term maintenance of steady-state exenatide (exendin-4) plasma and target levels in 6-hydroxydopamine (6-OHDA)-pretreated animals. Additionally, pre- or post-treatment with PT320 mitigated the early stage of 6-OHDA-induced dopaminergic neurodegeneration. The purpose of this study was to evaluate the effect of PT320 on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced abnormal involuntary movements (AIMs) in the rat 6-OHDA model of Parkinson's disease. METHODS: Adult male Sprague-Dawley rats were unilaterally lesioned in the right medial forebrain bundle by 6-OHDA. L-DOPA and benserazide were given daily for 22 days, starting from 4 weeks after lesioning. PT320 was co-administered weekly for 3 weeks. AIM was evaluated on days 1, 16, and 22 after initiating L-DOPA/benserazide + PT320 treatment. Brain tissues were subsequently collected for HPLC measurements of dopamine (DA) and metabolite concentrations. RESULTS: L-DOPA/benserazide increased AIMs of limbs and axial as well as the sum of all dyskinesia scores (ALO) over 3 weeks. PT320 significantly reduced the AIM scores of limbs, orolingual, and ALO. Although PT320 did not alter DA levels in the lesioned striatum, PT320 significantly attenuated 6-OHDA-enhanced DA turnover. CONCLUSION: PT320 attenuates L-DOPA/benserazide-induced dyskinesia in a 6-OHDA rat model of PD and warrants clinical evaluation to mitigate Parkinson's disease in humans.

Downregulation of α-Synuclein Protein Levels by an Intracellular Single-Chain Antibody.

BACKGROUND: Accumulation of α-synuclein (αSyn) in the dopaminergic neurons is a common pathology seen in patients with Parkinson's disease (PD). Overproduction of αSyn potentiates the formation of oligomeric αSyn aggregates and enhances dopaminergic neuron degeneration. Downregulating intracellular monomeric αSyn prevents the formation of αSyn oligomers and is a potential therapeutic strategy to attenuate the progression of PD. OBJECTIVE: The purpose of this study is to investigate the efficacy of gene delivery of αSyn-specific single-chain antibodies in vitro and in vivo. METHODS AND RESULTS: The plasmids for αSyn and selective antibodies (NAC32, D10, and VH14) were constructed and were transfected to HEK293 and SH-SY5Y cells. Co-expression of αSyn with NAC32, but not D10 or VH14, profoundly downregulated αSyn protein, but not αSyn mRNA levels in these cells. The interaction of αSyn and NAC32 antibody was next examined in vivo. Adeno-associated virus (AAV)-αSyn combined with AAV-NAC32 or AAV-sc6H4 (a negative control virus) were stereotactically injected into the substantia nigra of adult rats. AAV-NAC32 significantly reduced AAV-encoded αSyn levels in the substantia nigra and striatum and increased tyrosine hydroxylase immunoreactivity in the striatum. Also, in the animals injected with AAV-NAC32 alone, endogenous αSyn protein levels were significantly downregulated in the substantia nigra. CONCLUSION: Our data suggest that AAV-mediated gene transfer of NAC32 is a feasible approach for reducing the expression of target αSyn protein in brain.

Post-treatment with Posiphen Reduces Endoplasmic Reticulum Stress and Neurodegeneration in Stroke Brain.

Acetylcholinesterase (AChE) inhibitors have protective and anti-inflammatory actions against brain injury, mediated by nicotinic α7 cholinergic receptor activation. The use of AChE inhibitors in patients is limited by systemic cholinergic side effects. Posiphen, a stereoisomer of the AChE inhibitor Phenserine, lacks AChE inhibitor activity. The purpose of this study is to determine the protective effect of Posiphen in cellular and animal models of stroke. Both Posiphen and Phenserine reduced glutamate-mediated neuronal loss in co-cultures of primary cortical cells and microglia. Phenserine-, but not Posiphen-, mediated neuroprotection was diminished by the nicotinic α7 receptor antagonist methyllycaconitine. Posiphen antagonized NMDA-mediated Ca++ influx, thapsigargin-mediated neuronal loss and ER stress in cultured cells. Early post-treatment with Posiphen reduced ER stress signals, IBA1 immunoreactivity, TUNEL and infarction in the ischemic cortex, as well as neurological deficits in stroke rats. These findings indicate that Posiphen is neuroprotective against stroke through regulating Ca++i and ER stress.

Human Milk Oligosaccharide 2'-Fucosyllactose Reduces Neurodegeneration in Stroke Brain.

2'-Fucosyllactose (2'-FL) is a major oligosaccharide in human milk and is present at trace levels in cow milk. 2'-FL reduces inflammation in the gastrointestinal tract. Its action in the central nervous system has not been well characterized. The purpose of this study is to determine 2'-FL-mediated neural protection and repair in culture and stroke brain. In rat primary cortical neuronal cultures, 2'-FL significantly antagonized N-methyl-D-aspartate (NMDA) or glutamate-mediated changes in ATP production, MAP2 immunoreactivity, and TUNEL. The influx of Ca++ (Ca++i) was examined in primary cortical neurons expressing GCaMP5, an endogenous calcium probe. NMDA increased Ca++i; 2'-FL significantly attenuated this reaction. In a rat middle cerebral artery occlusion model of stroke, we found that intracerebroventricular pretreatment or oral posttreatment with 2'-FL significantly reduced brain infarction, mitigated microglial activation, improved locomotor activity, and upregulated brain-derived neurotrophic factor (BDNF) expression. Post-stroke delivery of 2'-FL increased bromodeoxyuridine (BrdU) labeling in the perilesioned area. These BrdU cells co-expressed NeuN, or nestin, or GFAP. Using subventricular Matrigel cultures, we demonstrated that 2'-FL increased cell migration from subventricular zone explant. This response was reduced by anti-BDNF blocking antibody. In conclusion, our data suggest that 2'-FL has neuroprotective action through inhibition of Ca++i, inflammation, and apoptosis. Posttreatment with 2'-FL facilitates neural repair in stroke brain.

Translating intracarotid artery transplantation of bone marrow-derived NCS-01 cells for ischemic stroke: Behavioral and histological readouts and mechanistic insights into stem cell therapy.

The present study used in vitro and in vivo stroke models to demonstrate the safety, efficacy, and mechanism of action of adult human bone marrow-derived NCS-01 cells. Coculture with NCS-01 cells protected primary rat cortical cells or human neural progenitor cells from oxygen glucose deprivation. Adult rats that were subjected to middle cerebral artery occlusion, transiently or permanently, and subsequently received intracarotid artery or intravenous transplants of NCS-01 cells displayed dose-dependent improvements in motor and neurological behaviors, and reductions in infarct area and peri-infarct cell loss, much better than intravenous administration. The optimal dose was 7.5 × 106 cells/mL when delivered via the intracarotid artery within 3 days poststroke, although therapeutic effects persisted even when administered at 1 week after stroke. Compared with other mesenchymal stem cells, NCS-01 cells ameliorated both the structural and functional deficits after stroke through a broad therapeutic window. NCS-01 cells secreted therapeutic molecules, such as basic fibroblast growth factor and interleukin-6, but equally importantly we observed for the first time the formation of filopodia by NCS-01 cells under stroke conditions, characterized by cadherin-positive processes extending from the stem cells toward the ischemic cells. Collectively, the present efficacy readouts and the novel filopodia-mediated mechanism of action provide solid lab-to-clinic evidence supporting the use of NCS-01 cells for treatment of stroke in the clinical setting.

Enhanced survival of human-induced pluripotent stem cell transplant in parkinsonian rat brain by locally applied cyclosporine.

A major limitation with cell transplantation in patients is the unimpressive number of cells survived. The death of grafted cells involves apoptosis and immunorejection. In this review, we encapsulate the recent preclinical development that improves the survival of grafted cells and mitigates the immunorejection of human-induced pluripotent stem cells (iPSCs) through co-grating nanoparticles-containing cyclosporine A (NanoCsA) in hemiparkinsonian rats. The study supported the notion that NanoCsA allows for long-lasting CsA discharge and limits immunorejection of human iPSC xenograft in a 6-hydroxydopamine Parkinson's disease rat model.

NanoCsA improves the survival of human iPSC transplant in hemiparkinsonian rats.

Increasing evidence has supported that transplantation of human stem cells induces neuroprotective and reparative effects in animal models of Parkinson's disease (PD). However, without systemic immunosuppressive therapy, most of these grafted cells are rejected by the hosts. Long term and systemic injection of cyclosporine-A (CsA) is required to maintain the survival of grafted cells. The purpose this study is to examine a new treatment strategy to suppress the immunorejection by locally co-grafting of polylactic/glycolic acid nanoparticles containing CsA (NanoCsA) with differentiated human induced pluripotent stem cells (iPSCs). In the in vitro media, NanoCsA provided sustained release of CsA for >6 weeks. The differentiated human iPSCs were co-grafted with NanoCsA or NanoVeh (nanoparticle without CsA) to the striatum of unilaterally 6-hydroxydopamine -lesioned rats. NanoCsA/iPSCs co-graft significantly improved locomotor activity compared to NanoVeh/iPSCs co-grafts or iPSC grafts + sytemic CsA at 1 month after transplantation. Brain tissues were collected for measurements of tyrosine hydroxylase (TH) and human marker Stem121 immunoreactivity. Cografting with NanoCsA/iPSCs, compared to NanoVeh/iPSCs, significantly increased TH and Stem121 immunoreactivity as well as tumor formation in the lesioned striatum. Taken together, our study supports that NanoCsA provides long-lasting CsA release and reduces immunorejection of human iPSCs xenograft in a 6-hydroxydopamine rat model of PD.

Pifithrin-Alpha Reduces Methamphetamine Neurotoxicity in Cultured Dopaminergic Neurons.

Methamphetamine (Meth) is a widely abused stimulant. High-dose Meth induces degeneration of dopaminergic neurons through p53-mediated apoptosis. A recent study indicated that treatment with the p53 inhibitor, pifithrin-alpha (PFT-α), antagonized Meth-mediated behavioral deficits in mice. The mechanisms underpinning the protective action of PFT-α against Meth have not been identified, and hence, their investigation is the focus of this study. Primary dopaminergic neuronal cultures were prepared from rat embryonic ventral mesencephalic tissue. High-dose Meth challenge reduced tyrosine hydroxylase immunoreactivity and increased terminal deoxynucleotidyl transferase-mediated dNTP nick-end labeling (TUNEL) labeling. PFT-α significantly antagonized these responses. PFT-α also reduced Meth-activated translocation of p53 to the nucleus, an initial step before transcription. Previous studies have indicated that p53 can also activate cell death through transcription-independent pathways. We found that PFT-α attenuated endoplasmic reticulum (ER) stressor thapsigargin (Tg)-mediated loss of dopaminergic neurons. ER stress was further monitored through the release of Gaussia luciferase (GLuc) from SH-SY5Y cells overexpressing GLuc-based Secreted ER Calcium-Modulated Protein (GLuc-SERCaMP). Meth or Tg significantly increased GLuc release in to the media, with PFT-α significantly reducing GLuc release. Additionally, PFT-α significantly attenuated Meth-induced CHOP expression. In conclusion, our data indicate that PFT-α is neuroprotective against Meth-mediated neurodegeneration via transcription-dependent nuclear and -independent cytosolic ER stress pathways.

Wharton' jelly mesenchymal stromal cell therapy for ischemic brain injury.

Increasing evidence have supported that Wharton's jelly mesenchymal stem cell (WJ-MSCs) have immunomodulatory and protective effects against several diseases including kidney, liver pathologies, and heart injury. Few in vitro studies have reported that WJ-MSCs reduced inflammation in hippocampal slices after oxygen-glucose deprivation. We recently reported the neuroprotective effects of human WJ-MSCs (hWJ-MSCs) in rats exposed to a transient right middle cerebral artery occlusion. hWJ-MSCs transplantation significantly reduced brain infarction and microglia activation in the penumbra leading with a significant reduction of neurological deficits. Interestingly, the grafted hWJ-MSCs in the ischemic core were mostly incorporated into IBA1 (+) cells, suggesting that hWJ-MSCs were immunorejected by the host. The immune rejection of hWJ-MSCs was reduced in after cyclosporine A treatment. Moreover, the glia cell line-derived neurotrophic factor expression was significantly increased in the host brain after hWJ-MSCs transplantation. In conclusion, these results suggest that the protective effect of hWJ-MSCs may be due to the secretion of trophic factors rather than to the survival of grafted cells. This paper is a review article. Referred literature in this paper has been listed in the references section. The data sets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors' experiences.

Neuroprotective Action of Human Wharton's Jelly-Derived Mesenchymal Stromal Cell Transplants in a Rodent Model of Stroke.

Wharton's jelly-derived mesenchymal stromal cells (WJ-MSCs) have distinct immunomodulatory and protective effects against kidney, liver, or heart injury. Limited studies have shown that WJ-MSCs attenuates oxygen-glucose deprivation-mediated inflammation in hippocampal slices. The neuroprotective effect of intracerebral WJ-MSC transplantation against stroke has not been well characterized. The purpose of this study was to examine the neuroprotective effect of human WJ-MSC (hWJ-MSC) transplants in an animal model of stroke. Adult male Sprague-Dawley rats were anesthetized and placed in a stereotaxic frame. hWJ-MSCs, pre-labeled with chloromethyl benzamide 1,1'-dioctadecyl-3,3,3'3'- tetramethylindocarbocyanine perchlorate (CM-Dil), were transplanted to the right cerebral cortex at 10 min before a transient (60 min) right middle cerebral artery occlusion (MCAo). Transplantation of hWJ-MSCs significantly reduced neurological deficits at 3 and 5 days after MCAo. hWJ-MSC transplants also significantly reduced brain infarction and microglia activation in the penumbra. Grafted cells carrying CM-Dil fluorescence were identified at the grafted site in the ischemic core; these cells were mostly incorporated into ionized calcium-binding adaptor molecule (+) cells, suggesting these xenograft cells were immuno-rejected by the host. In another set of animals, hWJ-MSCs were transplanted in cyclosporine (CsA)-treated rats. hWJ-MSC transplants significantly reduced brain infarction, improved neurological function, and reduced neuroinflammation. Less phagocytosis of CM-dil-labeled grafted cells was found in the host brain after CsA treatment. Transplantation of hWJ-MSC significantly increased glia cell line-derived neurotrophic factor expression in the host brain. Taken together, our data support that intracerebral transplantation of hWJ-MSCs reduced neurodegeneration and inflammation in the stroke brain. The protective effect did not depend on the survival of grafted cells but may be indirectly mediated through the production of protective trophic factors from the transplants.