Osthole augments therapeutic efficiency of neural stem cells-based therapy in experimental autoimmune encephalomyelitis

Astragalus polysaccharides promote neural stem cells-derived oligodendrogenesis through attenuating CD8+T cell infiltration in experimental autoimmune encephalomyelitis

Endogenous neural stem cells (NSCs) have the potential to generate remyelinating oligodendrocytes, which play an important role in multiple sclerosis (MS). However, the differentiation of NSCs into oligodendrocytes is insufficient, which is considered a major cause of remyelination failure. Our previous work reported that Astragalus polysaccharides (APS) had a neuroprotective effect on experimental autoimmune encephalomyelitis (EAE) mice. However, it remains unclear whether APS regulate NSCs differentiation in EAE mice. In this study, our data illustrated that APS administration could promote NSCs in the subventricular zone (SVZ) to differentiate into oligodendrocytes. Furthermore, we found that APS significantly improved neuroinflammation and inhibited CD8+T cell infiltration into SVZ of EAE mice. We also found that MOG35-55-specific CD8+T cells suppressed NSCs differentiation into oligodendrocytes by secreting IFN-γ, and APS facilitated the differentiation of NSCs into oligodendrocytes which was related to decreased IFN-γ secretion. In addition, APS treatment did not show a better effect on the NSCs-derived oligodendrogenesis after CD8+T cell depletion. This present study demonstrated that APS alleviated neuroinflammation and CD8+T cell infiltration into SVZ to induce oligodendroglial differentiation, and thus exerted neuroprotective effect. Our findings revealed that reducing the infiltration of CD8+T cells might contribute to enhancing NSCs-derived neurogenesis. And APS might be a promising drug candidate to treat MS.

Behavioral, neuroplasticity and metabolic effects of 7,8-dihydroxy-4-methylcoumarin associated with physical activity in mice

The search for strategies to develop resilience against metabolic and neuropsychiatric disorders has motivated the clinical and experimental assessment of early life interventions such as lifestyle-based and use of unconventional pharmacological compounds. In this study, we assessed the effects of voluntary physical activity and 7,8-Dihydroxy-4-methylcoumarin (DHMC), independently or in combination, over mice physiological and behavioral parameters, adult hippocampal and hypothalamic neurogenesis, and neurotrophic factors expression in the hypothalamus. C57Bl/6J mice were submitted to a 29-day treatment with DHMC and allowed free access to a running wheel. We found that DHMC treatment alone reduced fasting blood glucose levels. Moreover, physical activity showed an anxiolytic effect in the elevated plus maze task and DHMC produced additional anxiolytic behavior, evidenced by reduced activity during the light cycle in the physical activity group. Although we did not find any differences in hypothalamic or hippocampal adult neurogenesis, DHMC increased gene expression levels of VEGF, which was correlated to the reduced fasting glucose levels. In conclusion, our data emphasize the potential of physical activity in reducing development of neuropsychiatric conditions, such as anxiety, and highlights DHMC as an attractive compound to be investigated in future studies addressing neuropsychiatric disorders associated with metabolic conditions.

Osthole Ameliorates Estrogen Deficiency-Induced Cognitive Impairment in Female Mice

Loss of endogenous estrogen and dysregulation of the estrogen receptor signaling pathways are associated with an increase in risk for cognitive deficit and depression in women after menopause. Estrogen therapy for menopause increases the risk of breast and ovarian cancers, and stroke. Therefore, it is critical to find an alternate treatment for menopausal women. Osthole (OST), a coumarin, has been reported to have neuroprotective effects. This study examined whether OST improves ovariectomy (OVX)-induced cognitive impairment, and alleviates anxiety- and depression-like behaviors induced by OVX in mice. Adult female C57BL/6J mice were ovariectomized and then treated with OST at a dose of 30 mg/kg for 14 days. At the end of the treatment period, behavioral tests were used to evaluate spatial learning and memory, recognition memory, anxiety- and depression-like behaviors. A cohort of the mice were sacrificed after 14 days of OST treatment and their hippocampi were collected for measurement of the proteins of interest using western blot. OVX-induced alteration in the levels of proteins was accompanied by cognitive deficit, anxiety- and depression-like behaviors. OST treatment improved cognitive deficit, alleviated anxiety- and depression-like behaviors induced by OVX, and reversed OVX-induced alterations in the levels of synaptic proteins and ERα, BDNF, TrKB, p-CREB, p-Akt and Rac1 in the hippocampus. Therefore, reversal of OVX-induced decrease in the levels of hippocampal proteins by OST might contribute to the effects of OST on improving cognitive deficit and alleviating anxiety- and depression-like behaviors induced by OVX.

Multifunctional osthole liposomes and brain targeting functionality with potential applications in a mouse model of Alzheimer's disease

Osthole (Ost) is a coumarin compound and a potential drug for Alzheimer's disease (AD). However, the effectiveness of Ost is limited by solubility, bioavailability, and low permeability of the blood-brain barrier. In this study, we constructed Ost liposomes with modified CXCR4 on the surface (CXCR4-Ost-Lips), and investigated the intracellular distribution of liposomes in APP-SH-SY5Y cells. In addition, the neuroprotective effect of CXCR4-Ost-Lips was examined in vitro and in vivo. The results showed that CXCR4-Ost-Lips increased intracellular uptake by APP-SH-SY5Y cells and exerted a cytoprotective effect in vitro. The results of Ost brain distribution showed that CXCR4-Ost-Lips prolonged the cycle time of mice and increased the accumulation of Ost in the brain. In addition, CXCR4-Ost-Lips enhanced the effect of Ost in relieving AD-related pathologies. These results indicate that CXCR4-modified liposomes are a potential Ost carrier to treat AD.

Osthole attenuates ovalbumin‑induced lung inflammation via the inhibition of IL‑33/ST2 signaling in asthmatic mice

Asthma is a common chronic inflammatory airway disease. Recent studies have reported that interleukin (IL)-33 is a potential link between the airway epithelium and Th2-type inflammatory responses, which are closely related to the progression of asthma. The IL-33 receptor, ST2, is highly expressed in group 2 innate lymphoid cells (ILC2s), Th2 cells, mast cells, eosinophils and natural killer (NK) cells. Cnidii Fructus is a Chinese herb with a long history of use in the treatment of asthma in China. Osthole is one of the major components of Cnidii Fructus. The present study examined the anti-asthmatic effects of osthole in mice and aimed to elucidate the underlying mechanisms involving the IL-33/ST2 pathway. BALB/c mice were sensitized and challenged with ovalbumin and then treated with an intraperitoneal injection of osthole (25 and 50 mg/kg). Subsequently, the airway hyper-responsiveness (AHR) and inflammation of the lungs were evaluated. The amounts of IL-4, IL-5, IL-13, interferon (IFN)-γ and IL-33 in the bronchoalveolar lavage fluid (BALF) were measured by Luminex assay and their mRNA levels in the lungs were measured by reverse transcription-quantitative PCR. The histopathology of the lungs was performed with H&E, PAS and Masson's staining. The expression of ST2 in the lungs was evaluated by immunohistochemistry. The data demonstrated that osthole markedly reduced AHR and decreased the number of eosinophils and lymphocytes in BALF. It was also observed that osthole significantly inhibited the release of Th2-type cytokines (IL-4, IL-5 and IL-13) and upregulated the IFN-γ level in BALF. Moreover, osthole significantly attenuated the IL-33 and ST2 expression in the lungs of asthmatic mice. On the whole, osthole attenuated ovalbumin-induced lung inflammation through the inhibition of IL-33/ST2 signaling in an asthmatic mouse model. These results suggest that osthole is a promising target for the development of an asthma medication.

The ceramide-S1P pathway as a druggable target to alleviate peripheral neuropathic pain

Introduction: Neuropathic pain disorders are diverse, and the currently available therapies are ineffective in the majority of cases. Therefore, there is a major need for gaining novel mechanistic insights and developing new treatment strategies for neuropathic pain. Areas covered: We performed an in-depth literature search on the molecular mechanisms and systemic importance of the ceramide-to-S1P rheostat regulating neuron function and neuroimmune interactions in the development of neuropathic pain. Expert opinion: The S1P receptor modulator FTY720 (fingolimod, Gilenya®), LPA receptor antagonists and several mechanistically related compounds in clinical development raise great expectations for treating neuropathic pain disorders. Research on S1P receptors, S1P receptor modulators or SPHK inhibitors with distinct selectivity, pharmacokinetics and safety must provide more mechanistic insight into whether they may qualify as useful treatment options for neuropathic pain disorders. The functional relevance of genetic variations within the ceramide-to-S1P rheostat should be explored for an enhanced understanding of neuropathic pain pathogenesis. The ceramide-to-S1P rheostat is emerging as a critically important regulator hub of neuroimmune interactions along the pain pathway, and improved mechanistic insight is required to develop more precise and effective drug treatment options for patients suffering from neuropathic pain disorders.

Osthole ameliorates cognitive impairments via augmenting neuronal population in APP / PS1 transgenic mice

Alzheimer's disease (AD) is a neurodegenerative disorder with notable factors of dysfunction in multiple neurological changes, encompassing neuronal loss in the frontal cortex and hippocampal regions. Dysfunction of proliferation and self-renewal of neural stem cells (NSCs) was observed in AD patients and animals. Thereby, mobilizing endogenous neurogenesis by pharmacological agents would provide a promising route for neurodegeneration. Osthole (Ost), a natural coumarin derivative, has been reported to exert extensive neuroprotective effects in AD. However, whether ost can facilitate endogenous neurogenesis against AD in vivo is still unknown. In this study, by using Morris water maze (MWM) test, hematoxylin-eosin (HE) staining, Nissl staining, immunofluorescence analysis and western blot, we demonstrated that oral administration of ost could improve the learning and memory function, inhibit neuronal apoptosis, elevate the expression of glial cell line derived neurotrophic factor (GDNF), synaptophysin (SYP) and postsynaptic density protein 95 (PSD95). Moreover, ost could remarkably enhance proliferation of NSCs and increase the amount of mature neurons in APP/PS1 transgenic mice. Together, our findings demonstrated that ost possessed the ability of promoting endogenous neurogenesis and ost could be served as a plausible agent to reverse or slow down the progress of AD.

Effect of Polymer Permeability and Solvent Removal Rate on In Situ Forming Implants: Drug Burst Release and Microstructure

To explore the mechanism of drug release and depot formation of in situ forming implants (ISFIs), osthole-loaded ISFIs were prepared by dissolving polylactide, poly(lactide-co-glycolide), polycaprolactone, or poly(trimethylene carbonate) in different organic solvents, including N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and triacetin (TA). Drug release, polymer degradation, solvent removal rate and depot microstructure were examined. The burst release effect could be reduced by using solvents exhibit slow forming phase inversion and less permeable polymers. Both the drug burst release and polymer depot microstructure were closely related to the removal rate of organic solvent. Polymers with higher permeability often displayed faster drug and solvent diffusion rates. Due to high polymer-solvent affinity, some of the organic solvent remained in the depot even after the implant was completely formed. The residual of organic solvent could be predicted by solubility parameters. The ISFI showed a lower initial release in vivo than that in vitro. In summary, the effects of different polymers and solvents on drug release and depot formation in ISFI systems were extensively investigated and discussed in this article. The two main factors, polymer permeability and solvent removal rate, were involved in different stages of drug release and depot formation in ISFI systems.

Development of glial restricted human neural stem cells for oligodendrocyte differentiation in vitro and in vivo

In this study, we have developed highly expandable neural stem cells (NSCs) from HESCs and iPSCs that artificially express the oligodendrocyte (OL) specific transcription factor gene Zfp488. This is enough to restrict them to an exclusive oligodendrocyte progenitor cell (OPC) fate during differentiation in vitro and in vivo. During CNS development, Zfp488 is induced during the early stages of OL generation, and then again during terminal differentiation of OLs. Interestingly, the human ortholog Znf488, crucial for OL development in human, has been recently identified to function as a dorsoventral pattering regulator in the ventral spinal cord for the generation of P1, P2/pMN, and P2 neural progenitor domains. Forced expression of Zfp488 gene in human NSCs led to the robust generation of OLs and suppression of neuronal and astrocyte fate in vitro and in vivo. Zfp488 expressing NSC derived oligodendrocytes are functional and can myelinate rat dorsal root ganglion neurons in vitro, and form myelin in Shiverer mice brain in vivo. After transplantation near a site of demyelination, Zfp488 expressing hNSCs migrated to the lesion and differentiated into premyelinating OLs. A certain fraction also homed in the subventricular zone (SVZ). Zfp488-ZsGreen1-hNSC derived OLs formed compact myelin in Shiverer mice brain seen under the electron microscope. Transplanted human neural stem cells (NSC) that have the potential to differentiate into functional oligodendrocytes in response to remyelinating signals can be a powerful therapeutic intervention for disorders where oligodendrocyte (OL) replacement is beneficial.

Osthole alleviates inflammation by down-regulating NF-κB signaling pathway in traumatic brain injury

Traumatic brain injury (TBI) is a common neurotrosis disorder of the central nervous system (CNS), which has dramatic consequences on the integrity of damaged tissue. In this study, we investigated the neuroprotective effect and anti-inflammatory actions of osthole, a natural coumarin derivative, in both in vivo and in vitro TBI models. We first prepared a mouse model of cortical stab wound brain injury, investigated the capacity for osthole to prevent secondary brain injury and further examined the underlying mechanism. We revealed that osthole significantly improved the neurological function, increased the number of neurons beside injured site. Additionally, osthole treatment reduced the expression of microglia and glial scar, lowered the level of the proinflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and blocked the activation of nuclear factor kappa B (NF-κB). Furthermore, the protective effect of osthole was also examined in SH-SY5Y cells subjected to scratch injury. Treatment of osthole prominently suppressed cell apoptosis and inflammatory factors release by blocking injury-induced IκB-α phosphorylation and NF-κB translocation, and upregulated the IκB-α which functions in the NF-κB signaling pathway of SH-SY5Y cells. However, NF-κB signaling pathway was inhibited by pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, the anti-inflammatory effect of osthole was abolished. In conclusion, our findings demonstrated that osthole attenuated inflammatory response by inhibiting the NF-κB pathway in TBI.

Osthole alleviates MPTP-induced Parkinson's disease mice by suppressing Notch signaling pathway

Objectives: Parkinson's disease (PD) is an age-related neurodegenerative disease characterized by motor dysfunctions. Dopaminergic neuron loss, inflammation and oxidative stress responses play key roles in the pathogenisis of PD. Osthole (Ost), a natural coumarin derivative, isolated from various herbs such as Cnidium monnieri (L.), has anti-inflammatory, anti-apoptotic and anti-oxidative stress properties. However, whether it has effects on PD is unknown. Methods: In this study, mice were subjected to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) injection to induce PD symptoms, and treated with osthole. Stepping and cylinder tests were performed to determine their motor function. Immunohistochemical and immunofluorescence staining were performed to detect tyrosine hydroxylase (TH) and ionized calcium binding adaptor molecule 1 (Iba-1). The expression levels of inflammatory cytokines and oxidative stress factors were detected by qPCR and ELISA. Notch signaling pathway was investigated by western blot. Results: We found that injection of MPTP induced motor deficits in mice, enhanced the loss dopaminergic neurons and the activation of microglia, increased inflammatory and oxidative stress responses, and inhibited Notch signaling pathway. Osthole treatment suppressed theses MPTP-induced alterations. Conclusion: In conclusion, osthole attenuates PD symptoms by suppressing Notch signaling pathway.

Combination Therapy With Fingolimod and Neural Stem Cells Promotes Functional Myelination in vivo Through a Non-immunomodulatory Mechanism

Myelination, which occurs predominantly postnatally and continues throughout life, is important for proper neurologic function of the mammalian central nervous system (CNS). We have previously demonstrated that the combination therapy of fingolimod (FTY720) and transplanted neural stem cells (NSCs) had a significantly enhanced therapeutic effect on the chronic stage of experimental autoimmune encephalomyelitis, an animal model of CNS autoimmunity, compared to using either one of them alone. However, reduced disease severity may be secondary to the immunomodulatory effects of FTY720 and NSCs, while whether this therapy directly affects myelinogenesis remains unknown. To investigate this important question, we used three myelination models under minimal or non-inflammatory microenvironments. Our results showed that FTY720 drives NSCs to differentiate into oligodendrocytes and promotes myelination in an ex vivo brain slice culture model, and in the developing CNS of healthy postnatal mice in vivo. Elevated levels of neurotrophic factors, e.g., brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor, were observed in the CNS of the treated infant mice. Further, FTY720 and NSCs efficiently prolonged the survival and improved sensorimotor function of shiverer mice. Together, these data demonstrate a direct effect of FTY720, beyond its known immunomodulatory capacity, in NSC differentiation and myelin development as a novel mechanism underlying its therapeutic effect in demyelinating diseases.

Osthole Delays Tert-Butyl Hydroperoxide-Induced Premature Senescence in Neural Stem Cells

In our previous study, we found that osthole could promote the ability of proliferation and differentiation in normal neural stem cells (NSCs) under normal condition. Then, we used tert-butyl hydroperoxide (t-BHP) to establish the model of senescence NSCs to detect the effects of osthole. Interestingly, the immunofluorescence results showed that osthole (100 μM) could enhance the ability of proliferation and differentiation, and CCK-8 assay results showed that osthole could also enhance the cell viabilities. Then, SA-β-gal assay results showed that osthole could decrease the positive of senescence cells. Flow cytometric analysis results showed that osthole could decrease the mixture of G0 and G1 phase. Reverse transcriptase (RT)-polymerase chain reaction results showed that osthole could downregulate the expression of p16 mRNA, and western blot analysis results showed that the expressions of the target protein decreased in p16-pRb signaling pathway with osthole treatment. In conclusion, these results indicated that osthole could probably delay cells senescence through p16-pRb signaling pathway.

Osthole promotes endogenous neural stem cell proliferation and improved neurological function through Notch signaling pathway in mice acute mechanical brain injury

Mechanical brain injury (MBI) is a common neurotrosis disorder of the central nervous system (CNS), which has a higher mortality and disability. In the case of MBI, neurons death leads to loss of nerve function. To date, there was no satisfactory way to restore neural deficits caused by MBI. Endogenous neural stem cells (NSCs) can proliferate, differentiate and migrate to the lesions after brain injury, to replace and repair the damaged neural cells in the subventricular zone (SVZ), hippocampus and the regions of brain injury. In the present study, we first prepared a mouse model of cortical stab wound brain injury. Using the immunohistochemical and hematoxylin-eosin (H&E) staining method, we demonstrated that osthole (Ost), a natural coumarin derivative, was capable of promoting the proliferation of endogenous NSCs and improving neuronal restoration. Then, using the Morris water maze (MWM) test, we revealed that Ost significantly improved the learning and memory function in the MBI mice, increased the number of neurons in the regions of brain injury, hippocampus DG and CA3 regions. Additionally, we found that Ost up-regulated the expression of self-renewal genes Notch 1 and Hes 1. However, when Notch activity was blocked by the γ-secretase inhibitor DAPT, the expression of Notch 1 and Hes 1 mRNA was down-regulated, augmentation of NICD and Hes 1 protein was ameliorated, the proliferation-inducing effect of Ost was abolished. These results suggested that the effects of Ost were at least in part mediated by activation of Notch signaling pathway. Our findings support that Ost is a potential drug for treating MBI due to its neuronal restoration.

Neurotoxicity of fragrance compounds: A review

Fragrance compounds are chemicals belonging to one of several families, which are used frequently and globally in cosmetics, household products, foods and beverages. A complete list of such compounds is rarely found on the ingredients-list of such products, as "fragrance mixtures" are defined as "trade secrets" and thus protected by law. While some information regarding the general toxicity of some of these compounds is available, their neurotoxicity is known to a lesser extent. Here, we discuss the prevalence and neurotoxicity of fragrance compounds belonging to the three most common groups: phthalates, synthetic musks and chemical sensitizers.

Osthole Promotes Bone Fracture Healing through Activation of BMP Signaling in Chondrocytes

Osthole is a bioactive coumarin derivative and has been reported to be able to enhance bone formation and improve fracture healing. However, the molecular mechanism of Osthole in bone fracture healing has not been fully defined. In this study we determined if Osthole enhances bone fracture healing through activation of BMP2 signaling in mice. We performed unilateral open transverse tibial fracture procedure in 10-week-old C57BL/6 mice which were treated with or without Osthole. Our previous studies demonstrated that chondrocyte BMP signaling is required for bone fracture healing, in this study we also performed tibial fracture procedure in Cre-negative and Col2-Cre;Bmp2^flox/flox conditional knockout (KO) mice (Bmp2^Col2Cre) to determine if Osthole enhances fracture healing in a BMP2-dependent manner. Fracture callus tissues were collected and analyzed by X-ray, micro-CT (μCT), histology, histomorphometry, immunohistochemistry (IHC), biomechanical testing and quantitative gene expression analysis. In addition, mouse chondrogenic ATDC5 cells were cultured with or without Osthole and the expression levels of chondrogenic marker genes were examined. The results demonstrated that Osthole promotes bone fracture healing in wild-type (WT) or Cre^- control mice. In contrast, Osthole failed to promote bone fracture healing in Bmp2^Col2Creconditional KO mice. In the mice receiving Osthole treatment, expression of cartilage marker genes was significantly increased. We conclude that Osthole could promote bone strength and enhance fracture healing by activation of BMP2 signaling. Osthole may be used as an alternative approach in the orthopaedic clinic for the treatment of fracture healing.

Osthole Stimulated Neural Stem Cells Differentiation into Neurons in an Alzheimer's Disease Cell Model via Upregulation of MicroRNA-9 and Rescued the Functional Impairment of Hippocampal Neurons in APP/PS1 Transgenic Mice

Alzheimer's disease (AD) is the most serious neurodegenerative disease worldwide and is characterized by progressive cognitive impairment and multiple neurological changes, including neuronal loss in the brain. However, there are no available drugs to delay or cure this disease. Consequently, neuronal replacement therapy may be a strategy to treat AD. Osthole (Ost), a natural coumarin derivative, crosses the blood-brain barrier and exerts strong neuroprotective effects against AD in vitro and in vivo. Recently, microRNAs (miRNAs) have demonstrated a crucial role in pathological processes of AD, implying that targeting miRNAs could be a therapeutic approach to AD. In the present study, we investigated whether Ost could enhance cell viability and prevent cell death in amyloid precursor protein (APP)-expressing neural stem cells (NSCs) as well as promote APP-expressing NSCs differentiation into more neurons by upregulating microRNA (miR)-9 and inhibiting the Notch signaling pathway in vitro. In addition, Ost treatment in APP/PS1 double transgenic (Tg) mice markedly restored cognitive functions, reduced Aβ plague production and rescued functional impairment of hippocampal neurons. The results of the present study provides evidence of the neurogenesis effects and neurobiological mechanisms of Ost against AD, suggesting that Ost is a promising drug for treatment of AD or other neurodegenerative diseases.

Effect of Fingolimod on Neural Stem Cells: A Novel Mechanism and Broadened Application for Neural Repair

Inflammatory demyelination and axonal damage of the CNS are hallmarks of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Fingolimod (FTY720), the first FDA-approved oral medication for MS, suppresses acute disease but is less effective at the chronic stage, and whether it has a direct effect on neuroregeneration in MS and EAE remains unclear. Here we show that FTY720, at nanomolar concentrations, effectively protected survival of neural stem cells (NSCs) and enhanced their development into mature oligodendrocytes (OLGs) in vitro, primarily through the S1P3 and S1P5 receptors. In vivo, treatment with either FTY720 or NSCs alone had no effect on the secondary progressive stage of remitting-relapsing EAE, but a combination therapy with FTY720 and NSCs promoted significant recovery, including ameliorated clinical signs and CNS inflammatory demyelination, enhanced MBP synthesis and remyelination, inhibited axonal degeneration, and reduced astrogliosis. Moreover, FTY720 significantly improved incorporation and survival of transplanted NSCs in the CNS and drove their differentiation into more OLGs but fewer astrocytes, thus promoting remyelination and CNS repair processes in situ. Our data demonstrate a novel effect of FTY720 on NSC differentiation and remyelination, broadening its possible application to NSC-based therapy in the secondary progressive stage of MS.

Resveratrol defends blood-brain barrier integrity in experimental autoimmune encephalomyelitis mice

The mouse autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis (MS), is primarily characterized as dysfunction of the blood-brain barrier (BBB). Resveratrol exhibits anti-inflammatory, antioxidative, and neuroprotective activities. We investigated the beneficial effects of resveratrol in protecting the integrity of the BBB in EAE mice and observed improved clinical outcome in the EAE mice after resveratrol treatment. Evans blue (EB) extravasation was used to detect the disruption of BBB. Western blot were used to detected the tight junction proteins and adhesion molecules zonula occludens-1 (ZO-1), occludin, ICAM-1, and VCAM-1. Inflammatory factors inducible nitric oxide synthase (iNOS), IL-1β, and arginase 1 were evaluated by quantitative RT-PCR (qPCR) and IL-10 by ELISA. NADPH oxidase (NOX) levels were evaluated by qPCR, and its activity was analyzed by lucigenin-derived chemiluminescence. Resveratrol at doses of 25 and 50 mg/kg produced a dose-dependent decrease in EAE paralysis and EB leakage, ameliorated EAE-induced loss of tight junction proteins ZO-1, occludin, and claudin-5, as well as repressed the EAE-induced increase in adhesion proteins ICAM-1 and VCAM-1. In addition, resveratrol suppressed the EAE-induced overexpression of proinflammatory transcripts iNOS and IL-1β and upregulated the expression of anti-inflammatory transcripts arginase 1 and IL-10 cytokine in the brain. Furthermore, resveratrol downregulated the overexpressed NOX2 and NOX4 in the brain and suppressed NADPH activity. Resveratrol ameliorates the clinical severity of MS through maintaining the BBB integrity in EAE mice.

Neuroprotective Effect of Osthole on Neuron Synapses in an Alzheimer's Disease Cell Model via Upregulation of MicroRNA-9

Accumulation of β-amyloid peptide (Aβ) in the brain plays an important role in the pathogenesis of Alzheimer's disease (AD). It has been reported that osthole exerts its neuroprotective effect on neuronal synapses, but its exact mechanism is obscure. Recently, microRNAs have been demonstrated to play a crucial role in inducing synaptotoxicity by Aβ, implying that targeting microRNAs could be a therapeutic approach of AD. In the present study, we investigated the neuroprotective effects of osthole on a cell model of AD by transducing APP695 Swedish mutant (APP695swe, APP) into mouse cortical neurons and human SH-SY5Y cells. In this study, the cell counting kit CCK-8, apoptosis assay, immunofluorescence analysis, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction, and Western blot assay were used. We found that osthole could enhance cell viability, prevent cell death, and reverse the reduction of synaptic proteins (synapsin-1, synaptophysin, and postsynaptic density-95) in APP-overexpressed cells, which was attributed to increases in microRNA-9 (miR-9) expression and subsequent decreases in CAMKK2 and p-AMPKα expressions. These results demonstrated that osthole plays a neuroprotective activity role in part through upregulating miR-9 in AD.

LINGO-1-Fc-Transduced Neural Stem Cells Are Effective Therapy for Chronic Stage Experimental Autoimmune Encephalomyelitis

The chronic stage multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS), remains refractory to current treatments. This refractory nature may be due to the fact that current treatments are primarily immunomodulatory, which prevent further demyelination but lack the capacity to promote remyelination. Several approaches, including transplantation of neural stem cells (NSCs) or antagonists to LINGO-1, a key part of the receptor complex for neuroregeneration inhibitors, have been effective in suppressing the acute stage of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, their effect on the chronic stage EAE is not known. Here, we show that transplantation of NSCs had only a slight therapeutic effect when treatment started at the chronic stage of EAE (e.g., injected at day 40 postimmunization). However, NSCs engineered to produce LINGO-1-Fc, a soluble LINGO-1 antagonist, significantly promoted neurological recovery as demonstrated by amelioration of clinical signs, improvement in axonal integrity, and enhancement of oligodendrocyte maturation and neuron repopulation. Significantly enhanced NAD production and Sirt2 expression were also found in the CNS of mice treated with LINGO-1-Fc-producing NSC. Moreover, differentiation of LINGO-1-Fc-producing NSCs into oligodendrocytes in vitro was largely diminished by an NAMPT inhibitor, indicating that LINGO-1-Fc enhances the NAMPT/NAD/Sirt2 pathway. Together, our study establishes a CNS-targeted, novel LINGO-1-Fc delivery system using NSCs, which represents a novel and effective NSC-based gene therapy approach for the chronic stage of MS.

Arctigenin Treatment Protects against Brain Damage through an Anti-Inflammatory and Anti-Apoptotic Mechanism after Needle Insertion

Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in a stab wound injury (SWI). Subsequent secondary injury involves the release of inflammatory and apoptotic cytokines, which have dramatic consequences on the integrity of damaged tissue, leading to the evolution of a pericontusional-damaged area minutes to days after in the initial injury. The present study investigated the capacity for arctigenin (ARC) to prevent secondary brain injury and the determination of the underlying mechanism of action in a mouse model of SWI that mimics the process of CED. After CED, mice received a gavage of ARC from 30 min to 14 days. Neurological severity scores (NSS) and wound closure degree were assessed after the injury. Histological analysis and immunocytochemistry were used to evaluated the extent of brain damage and neuroinflammation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to detect universal apoptosis. Enzyme-linked immunosorbent assays (ELISA) was used to test the inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10) and lactate dehydrogenase (LDH) content. Gene levels of inflammation (TNF-α, IL-6, and IL-10) and apoptosis (Caspase-3, Bax and Bcl-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR). Using these, we analyzed ARC’s efficacy and mechanism of action. Results: ARC treatment improved neurological function by reducing brain water content and hematoma and accelerating wound closure relative to untreated mice. ARC treatment reduced the levels of TNF-α and IL-6 and the number of allograft inflammatory factor (IBA)- and myeloperoxidase (MPO)-positive cells and increased the levels of IL-10. ARC-treated mice had fewer TUNEL+ apoptotic neurons and activated caspase-3-positive neurons surrounding the lesion than controls, indicating increased neuronal survival. Conclusions: ARC treatment confers neuroprotection of brain tissue through anti-inflammatory and anti-apoptotic effects in a mouse model of SWI. These results suggest a new strategy for promoting neuronal survival and function after CED to improve long-term patient outcome.

Proliferation and Glia-Directed Differentiation of Neural Stem Cells in the Subventricular Zone of the Lateral Ventricle and the Migratory Pathway to the Lesions after Cortical Devascularization of Adult Rats

We investigated the effects of cortical devascularization on the proliferation, differentiation, and migration of neural stem cells (NSCs) in the subventricular zone (SVZ) of the lateral ventricle of adult rats. 60 adult male Wistar rats were randomly divided into control group and devascularized group. At 15 and 30 days after cerebral cortices were devascularized, rats were euthanized and immunohistochemical analysis was performed. The number of PCNA-, Vimentin-, and GFAP-positive cells in the bilateral SVZ of the lateral wall and the superior wall of the lateral ventricles of 15- and 30-day devascularized groups increased significantly compared with the control group (P < 0.05 and P < 0.01). The area density of PCNA-, Vimentin-, and GFAP-positive cells in cortical lesions of 15- and 30-day devascularized groups increased significantly compared with the control group (P < 0.05 and P < 0.01). PCNA-, GFAP-, and Vimentin-positive cells in the SVZ migrated through the rostral migratory stream (RMS), and PCNA-, GFAP-, and Vimentin-positive cells from both the ipsilateral and contralateral dorsolateral SVZ (dl-SVZ) migrated into the corpus callosum (CC) and accumulated, forming a migratory pathway within the CC to the lesioned site. Our study suggested that cortical devascularization induced proliferation, glia-directed differentiation, and migration of NSCs from the SVZ through the RMS or directly to the corpus callosum and finally migrating radially to cortical lesions. This may play a significant role in neural repair.

GDNF Enhances Therapeutic Efficiency of Neural Stem Cells-Based Therapy in Chronic Experimental Allergic Encephalomyelitis in Rat

Multiple sclerosis (MS) is an autoimmune disease in the CNS. The current immunomodulating drugs for MS do not effectively prevent the progressive neurological decline. Neural stem cells (NSCs) transplantation has been proven to promote repair and functional recovery of experimental allergic encephalomyelitis (EAE) animal model for MS, and glial cell line-derived neurotrophic factor (GDNF) has also been found to have capability of promoting axonal regeneration and remyelination of regenerating axons. In the present study, to assess whether GDNF would enhance therapeutic effect of NSCs for EAE, GDNF gene-modified NSCs (GDNF/NSCs) and native NSCs were transplanted into each lateral ventricle of rats at 10 days and rats were sacrificed at 60 days after EAE immunization. We found that NSCs significantly reduced the clinical signs, and GDNF gene-modification further promoted functional recovery. GDNF/NSCs more profoundly suppressed brain inflammation and improved density of myelin compared with NSCs. The survival of GDNF/NSCs was significantly higher than that of transplanted NSCs. Transplanted GDNF/NSCs, in contrast to NSCs, differentiated into more neurons and oligodendrocytes. Moreover, the mRNA expression of oligodendrocyte lineage cells in rats with GDNF/NSCs was significantly increased compared to rats with NSCs. These results suggest that GDNF enhances therapeutic efficiency of NSCs-based therapy for EAE.

Transplantation of Neural Stem Cells Cotreated with Thyroid Hormone and GDNF Gene Induces Neuroprotection in Rats of Chronic Experimental Allergic Encephalomyelitis

The present study investigates whether transplantation of NSCs treated with T3 alone (T3/NSCs), or in conjunction with GDNF gene (GDNF-T3/NSCs), provides a better therapeutic effect than NSCs for chronic EAE. EAE rats were, respectively, injected with NSCs, T3/NSCs, GDNF-T3/NSCs, and saline at 10 days and sacrificed at 60 days after EAE immunization. The three cell grafted groups showed a significant reduction in clinical scores, inflammatory infiltration, and demyelination compared with the saline-injected group, and among the cell grafted groups, the reduction in GDNF-T3/NSCs group was the most notable, followed by T3/NSCs group. Grafted T3/NSCs and GDNF-T3/NSCs acquired more MAP2, GalC, and less GFAP in brain compared with grafted NSCs, and grafted GDNF-T3/NSCs acquired most MAP2 and least GalC among the cell grafted groups. Furthermore, T3/NSCs and GDNF-T3/NSCs grafting increased the expression of mRNA for PDGFαR, GalC, and MBP in lesion areas of brain compared with NSCs grafting, and the expression of mRNA for GalC and MBP in GDNF-T3/NSCs group was higher than that in T3/NSCs group. In conclusion, T3/NSCs grafting, especially GDNF-T3/NSCs grafting, provides a better neuroprotective effect for EAE than NSCs transplantation.

Osthole promotes neuronal differentiation and inhibits apoptosis via Wnt/β-catenin signaling in an Alzheimer's disease model

Neurogenesis is the process by which neural stem cells (NSCs) proliferate and differentiate into neurons. This is diminished in several neurodegenerative disorders such as Alzheimer's disease (AD), which is characterized by the deposition of amyloid (A)β peptides and neuronal loss. Stimulating NSCs to replace lost neurons is therefore a promising approach for AD treatment. Our previous study demonstrated that osthole modulates NSC proliferation and differentiation, and may reduce Aβ protein expression in nerve cells. Here we investigated the mechanism underlying the effects of osthole on NSCs. We found that osthole enhances NSC proliferation and neuronal differentiation while suppressing apoptosis, effects that were exerted via activation of Wnt/β-catenin signaling. These results provide evidence that osthole can potentially be used as a therapeutic agent in the treatment of AD and other neurodegenerative disorders.

A mild and fast continuous-flow trifluoromethylation of coumarins with the CF3 radical derived from CF3SO2Na and TBHP

A mild and fast Cu(I)-catalyzed trifluoromethylation of coumarins with CF3SO2Na and TBHP in a continuous-flow reactor has been developed. This method is experimentally simple and carried out under mild conditions, affording the corresponding products in moderate to good yields, and showing wide substrate tolerance. The scale-up flow process results in an isolated yield of 68% and a productivity of 305 mg h(-1) of 3-trifluoromethyl-7-diethylamino-4-methyl coumarin when the concentration was increased five-fold. Given these features and the widespread applications of coumarins, this method may find use from laboratory to manufacturing.

Osthole confers neuroprotection against cortical stab wound injury and attenuates secondary brain injury

Background

Neuroendoscopy is an innovative technique for neurosurgery that can nonetheless result in traumatic brain injury. The accompanying neuroinflammation may lead to secondary tissue damage, which is the major cause of delayed neuronal death after surgery. The present study investigated the capacity of osthole to prevent secondary brain injury and the underlying mechanism of action in a mouse model of stab wound injury.

Methods

A mouse model of cortical stab wound injury was established by inserting a needle into the cerebral cortex for 20 min to mimic neuroendoscopy. Mice received an intraperitoneal injection of osthole 30 min after surgery and continued for 14 days. Neurological severity was evaluated 12 h and up to 21 days after the trauma. Brains were collected 3–21 days post-injury for histological analysis, immunocytochemistry, quantitative real-time PCR, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and enzyme-linked immunosorbent assays.

Results

Neurological function improved in mice treated with osthole and was accompanied by reduced brain water content and accelerated wound closure relative to untreated mice. Osthole treatment reduced the number of macrophages/microglia and peripheral infiltrating of neutrophils and lowered the level of the proinflammatory cytokines interleukin-6 and tumor necrosis factor α in the lesioned cortex. Osthole-treated mice had fewer TUNEL+ apoptotic neurons surrounding the lesion than controls, indicating increased neuronal survival.

Conclusions

Osthole reduced secondary brain damage by suppressing inflammation and apoptosis in a mouse model of stab wound injury. These results suggest a new strategy for promoting neuronal survival and function after neurosurgery to improve long-term patient outcome.