Ischemic preconditioning enhances neurogenesis in the subventricular zone

Ischemic preconditioning (IPC) before subsequent prolonged ischemia is considered an emerging endogenous means of ischemic brain protection. We tested whether IPC induces endogenous neurogenesis in the subventricular zone (SVZ) and angiogenesis in the peri-ischemic area. Middle cerebral artery occlusion was administered to rats by filament insertion for 10 min (IPC) and/or 2 h (prolonged focal ischemia [PFI]). IPC alone increased 5'-bromo-2'-deoxyuridine (BrdU) (+) cells 2.5-fold in the SVZ compared with controls at 7 days. The numbers of BrdU/doublecortin (Dcx) or BrdU/neuronal nuclei (NeuN) double-labeled cells also increased, but extents of BrdU/glial fibrillary acidic protein (GFAP) double-labeling in the SVZ were not different. The IPC+PFI group showed about a 40% reduction in infarct volume. PFI increased BrdU (+) cells in the SVZ, and this was greatly enhanced by IPC treatment. The number of BrdU/Dcx double-labeled cells was strongly increased in ischemic brains administered IPC. Differentiation into mature neurons was also enhanced at 14 and 28 days. In addition, IPC significantly promoted angiogenesis in the ischemic penumbra as indicated by von Willebrand factor (vWF) staining. Our results indicate that IPC enhances neurogenesis in the SVZ even without subsequent PFI, and also enhances neurogenesis and angiogenesis after subsequent PFI. We conclude that IPC confers neuroprotection, and also promotes endogenous neurogenesis and angiogenesis.     

Granulocyte colony stimulating factor decreases brain amyloid burden and reverses cognitive impairment in Alzheimer's mice

Granulocyte colony stimulating factor (G-CSF) is a multi-modal hematopoietic growth factor, which also has profound effects on the diseased CNS. G-CSF has been shown to enhance recovery from neurologic deficits in rodent models of ischemia. G-CSF appears to facilitate neuroplastic changes by both mobilization of bone marrow–derived cells and by its direct actions on CNS cells. The overall objective of the study was to determine if G-CSF administration in a mouse model of Alzheimer's disease (AD) (Tg APP/PS1) would impact hippocampal-dependent learning by modifying the underlying disease pathology. A course of s.c. administration of G-CSF for a period of less than three weeks significantly improved cognitive performance, decreased β-amyloid deposition in hippocampus and entorhinal cortex and augmented total microglial activity. Additionally, G-CSF reduced systemic inflammation indicated by suppression of the production or activity of major pro-inflammatory cytokines in plasma. Improved cognition in AD mice was associated with increased synaptophysin immunostaining in hippocampal CA1 and CA3 regions and augmented neurogenesis, evidenced by increased numbers of calretinin-expressing cells in dentate gyrus. Given that G-CSF is already utilized clinically to safely stimulate hematopoietic stem cell production, these basic research findings will be readily translated into clinical trials to reverse or forestall the progression of dementia in AD. The primary objective of the present study was to determine whether a short course of G-CSF administration would have an impact on the pathological hallmark of AD, the age-dependent accumulation of Aβ deposits, in a transgenic mouse model of AD (APP+ PS1; Tg). A second objective was to determine whether such treatment would impact cognitive performance in a hippocampal-dependent memory paradigm. To explain the G-CSF triggered amyloid reduction and associated reversal of cognitive impairment, several mechanisms of action were explored. (1) G-CSF was hypothesized to increase activation of resident microglia and to increase mobilization of marrow-derived microglia. The effect of G-CSF on microglial activation was examined by quantitative measurements of total microglial burden. To determine if G-CSF increased trafficking of marrow-derived microglia into brain, bone marrow–derived green fluorescent protein-expressing (GFP+) microglia were visualized in the brains of chimeric AD mice. (2) To assess the role of immune-modulation in mediating G-CSF effects, a panel of cytokines was measured in both plasma and brain. (3) To test the hypothesis that reduction of Aβ deposits can affect synaptic area, quantitative measurement of synaptophysin immunoreactivity in hippocampal CA1 and CA3 sectors was undertaken. (4) To learn whether enhanced hippocampal neurogenesis was induced by G-CSF treatment, numbers of calretinin-expressing cells were determined in dentate gyrus.     

CEPO经Mashl信号促进大鼠局部脑缺血后纹状体内神经发生

为检测氨甲酰化促红细胞叶三成素(CEPO)在大鼠脑缺血后发生过程中的作用及其相关信号通路,本实验将成年大鼠大脑中动脉栓塞(MCAO)后立即尾静脉给予CEPO(50μg/kg).结果显示:CEPO可显著降低大鼠MCAO后3 d梗塞面积,增加缺血侧神经于细胞增殖、促进神经干细胞分化成为神经元.CEPO的促神经发生效应与缺血侧纹状体内前神经元bHLH转录因子Mash1的表达上调密切相关.本结果提示CEPO对脑缺血具有神经保护作用,Mash1信号在缺血侧纹状体内可能介导CEPO增强的神经发生和神经元分化效应.     

Transforming growth factor β2 is able to modify mRNA levels and release of luteinizing hormone-releasing hormone in a immortalized hypothalamic cell line (GT1-1)

On the basis of our previous observations which indicated that transforming growth factor β1 (TGFβ1) affects the gene expression and the release of luteinizing hormone-releasing hormone (LHRH) in GT1-1 cells, we have presently evaluated whether also TGFβ2 might be effective on these parameters. The data here reported show that also TGFβ2 is able to affect LHRH dynamics, and that this action presents a different kinetics than that reported by TGFβ1. In particular TGFβ2 is able to facilitate LHRH release and to decrease the mRNA levels of this decapeptide. The present data have also shown that, GT1-1 cells express the messengers for the two most important receptors of the TGFβ family, namely TGFβRI and TGFβRII and consequently represent a target for the action of the different isoforms of TGFβ. Since the two isoforms of TGFβ are produced and released from astrocytes, the present data add new support to the hypothesis that astrocytes participate in the control of LHRH secretion in a paracrine fashion.     

Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

Transforming growth factor β (TGFβ) can inhibit the in vitro proliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1^-/- mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1^- pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1⁺ pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell development in vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.     

Cytotoxic T cells isolated from healthy donors and cancer patients kill TGFβ-expressing cancer cells in a TGFβ-dependent manner

Transforming growth factor-beta (TGFβ) is a highly potent immunosuppressive cytokine. Although TGFβ is a tumor suppressor in early/premalignant cancer lesions, the cytokine has several tumor-promoting effects in advanced cancer; abrogation of the antitumor immune response is one of the most important tumor-promoting effects. As several immunoregulatory mechanisms have recently been shown to be targets of specific T cells, we hypothesized that TGFβ is targeted by naturally occurring specific T cells and thus could be a potential target for immunomodulatory cancer vaccination. Hence, we tested healthy donor and cancer patient T cells for spontaneous T-cell responses specifically targeting 38 20-mer epitopes derived from TGFβ1. We identified numerous CD4⁺ and CD8⁺ T-cell responses against several epitopes in TGFβ. Additionally, several ex vivo responses were identified. By enriching specific T cells from different donors, we produced highly specific cultures specific to several TGFβ-derived epitopes. Cytotoxic CD8⁺ T-cell clones specific for both a 20-mer epitope and a 9-mer HLA-A2 restricted killed epitope peptide were pulsed in HLA-A2⁺ target cells and killed the HLA-A2⁺ cancer cell lines THP-1 and UKE-1. Additionally, stimulation of THP-1 cancer cells with cytokines that increased TGFβ expression increased the fraction of killed cells. In conclusion, we have shown that healthy donors and cancer patients harbor CD4⁺ and CD8⁺ T cells specific for TGFβ-derived epitopes and that cytotoxic T cells with specificity toward TGFβ-derived epitopes are able to recognize and kill cancer cell lines in a TGFβ-dependent manner.     

大鼠局灶性短暂脑缺血后前脑室下带的神经发生

目的：观察大鼠短暂性局灶性脑缺血后前脑室下带(SVZ)神经发生的增殖规律。方法：将SD大鼠随机分为正常对照组、假手术组和缺血实验组,缺血实验组再分为缺血后1、4、7、10、14d组。线栓法制作局灶性脑缺血模型;BrdU标记S期细胞并用免疫组织化学方法检测含BrdU的阳性细胞;测量SVZ区域BrdU阳性细胞核的总面积。结果：在缺血侧,缺血后4d BrdU阳性细胞核的总面积明显增加,7d时达到峰值,随后开始下降,在14d时明显下降,但仍高于正常对照组;在缺血对侧,该区域也表现出同样的表达规律,在缺血后10d达到峰值,但增幅较小。结论：短暂性局灶性脑缺血可促进前脑室下带的神经发生,提示成年脑有潜在的自我修复能力。     

Transplanted Late Outgrowth Endothelial Progenitor Cells as Cell Therapy Product for Stroke

Endothelial progenitor cells (EPCs) seem to be a promising option to treat patients with ischemic diseases. Here, we investigated the effects of late outgrowth EPCs, or endothelial colony-forming cells (ECFCs), a recently defined homogeneous subtype of EPCs, in a rat model of transient middle cerebral artery occlusion (MCAO). Either vehicle or 4.10⁶ ECFCs, isolated from human cord blood, were intravenously injected 24?h after 1?h MCAO in rats assigned to control and transplanted groups respectively. ¹¹¹In-oxine-labeled ECFCs specifically homed to ischemic hemisphere and CM-Dil prelabeled ECFCs preferentially settled in the inner boundary of the core area of transplanted animals. Although incorporation of cells into neovessels was hardly detectable, ECFCs transplantation was associated with a reduction in apoptotic cell number, an increase in capillary density and a stimulation of neurogenesis at the site of injury. These effects were associated with an increase in growth factors expression in homogenates from ischemic area and may be related to the secretion by ECFCs of soluble factors that could affect apoptosis, vascular growth and neurogenesis. Microscopic examination of the ischemic hemisphere showed that ECFCs transplantation was also associated with a reduction in reactive astrogliosis. In conclusion, we demonstrated that ECFCs injected 24?h after MCAO settled in the injured area and improved functional recovery. The neurological benefits may be linked to a reduction in ischemia-induced apoptosis and a stimulation of ischemia-induced angiogenesis and neurogenesis. These findings raise perspectives for the use of ECFCs as a well-characterized cell therapy product for optimal therapeutic outcome after stroke.     

The role of thromboxane prostanoid receptor signaling in gastric ulcer healing

The process of gastric ulcer healing includes cell migration, proliferation, angiogenesis and re‐epithelialization. Platelets contain angiogenesis stimulating factors that induce angiogenesis. Thromboxane A₂ (TXA₂) not only induces platelet activity but also angiogenesis. This study investigated the role of TXA₂ in gastric ulcer healing using TXA₂ receptor knockout (TPKO) mice. Gastric ulcer healing was suppressed by treatment with the TXA₂ synthase inhibitor OKY‐046 and the TXA₂ receptor antagonist S‐1452 compared with vehicle‐treated mice. TPKO showed delayed gastric ulcer healing compared with wild‐type mice (WT). The number of microvessels and CD31 expression were lower in TPKO than in WT mice, and TPKO suppressed the expression of transforming growth factor beta (TGF‐β) and vascular endothelial growth factor A (VEGF‐A) in areas around gastric ulcers. Immunofluorescence assays showed that TGF‐β and VEGF‐A co‐localized with platelets. Gastric ulcer healing was significantly reduced in WT mice transplanted with TPKO compared with WT bone marrow. These results suggested that TP signalling on platelets facilitates gastric ulcer healing through TGF‐β and VEGF‐A.     

Local Production of Interleukins and Growth Factors in External Genital Endometriosis

Secretion of some IL and growth factors (VEGF, IGF-I, TGFβ) by endometrial tissues and endometrioid heterotopies was studied in vitro in patients with external genital endometriosis of different severity. The production of IL-1β, IL-2, IL-6, and VEGF in the endometrium increased in severe external genital endometriosis, while the secretion of TGFβ decreased; hyperproduction of IL-2, IL-6, VEGF and decreased production of TGFβ were detected in endometrioid foci. Presumably, local cytokine imbalance and increased proliferative activity of endometrial cells are involved in the mechanisms of formation and functioning of endometrioid foci.__________Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 4, pp. 439–42, April, 2005     

Ultrasound-mediated microbubble destruction enhances the therapeutic effect of intracoronary transplantation of bone marrow stem cells on myocardial infarction

Objective: The combination of intracoronary transplantation and ultrasound-mediated microbubble destruction may promote effective and accurate delivery of bone marrow stem cells (BMSCs) into the infarct zone. To test this hypothesis in this study we examined the effectiveness of ultrasound-mediated microbubble destruction in combination with intracoronary transplantation of BMSCs for the treatment of myocardial infarction in canine model of acute myocardial infarction. Method: The dogs were randomly assigned to four groups: PBS, ultrasound-mediated microbubble destruction, BMSCs, BMSCs together with ultrasound-mediated microbubble destruction. At 28 days post-surgery, cardiac function and the percentage of perfusion defect area to total left ventricular perfusion area (DA%) were determined by myocardial contrast echocardiography. Nitro blue tetrazolium staining was performed to determine myocardial infarct size, hematoxylin and eosin staining for assessing microvascular injury, Masson’s staining for analyzing myocardial tissue collagen, immunohistochemical analysis of α-actin to measure cardiac contractile function and of BrdU-labeled myocardial cells to measure the number of the BMSCs homing to the infarcted region. Results: The transplantation of BMSCs significantly improved heart function and DA% (P < 0.05). The group that received ultrasound-mediated microbubble destruction with BMSCs transplantation showed the most improvement in heart function and DA% (P < 0.05). This group also showed a denser deposition of BMSCs in the coronary artery and more BrdU positive cells in the infarcted region, had the maximum number of α-actin positive cells, showed the smallest myocardial infarct area compared to other groups (P< 0.05). Conclusion: Ultrasound-mediated microbubble destruction increases the homing of BMSCs in the target area following intracoronary transplantation, which allows more BMSCs to differentiate into functional cardiomyocytes, thereby reducing myocardial infarct size and improving cardiac function.     

Enhancing neurogenesis and angiogenesis with target delivery of stromal cell derived factor-1α using a dual ionic pH-sensitive copolymer

In this study, we hypothesized that the delivery of molecules that regulate the microenvironment after a cerebral infarction can influence regeneration potential after a stroke. Stromal cell-derived factor-1α (SDF-1α) is a chemoattractant molecule that plays a pivotal role in recruiting endothelial progenitor cells (EPCs) to the infarct region after stroke. Increased SDF-1α expression leads to increased EPCs homing at the infarct region and induces neurogenesis, angiogenesis, neuroprotection, and stem cell homing. Thus, we evaluated the effects of targeted delivery of SDF-1α using a pH-sensitive polymer poly (urethane amino sulfamethazine) (PUASM), a synthetic macromolecule with potential for targeted drug delivery in acidic conditions, to enhance therapeutic neurogenesis and angiogenesis in a rat model of permanent middle cerebral artery occlusion. A dual ionic pH-sensitive copolymer PUASM-based random copolymer was designed and synthesized for the controlled release of SDF-1α in stroke. Owing to the unique characteristics of PUASM, it exhibited a dual ionic pH-sensitive property in an aqueous solution. At pH 8.5, the copolymer exhibited a negative charge and was water soluble. Interestingly, when the pH decreased to 7.4, PUASM could form a micelle and encapsulate protein effectively via the ionic interaction between a negatively charged polymer and a positively charged protein. At pH 5.5, the ionization of tertiary amines led to the disassembly of the micellar structure and released the protein rapidly. Then, we investigated the effect of systemic administration of SDF-1α-loaded pH-sensitive polymeric micelles in a stroke induced rat model. An enzyme-linked immunosorbent assay showed increased expression of SDF-1α in the ischemic region, indicating that the pH-sensitive micelles effectively delivered SDF-1α into the ischemic region. In order to observe the biodistribution of SDF-1α in the ischemic region, it was labeled with the near-infrared dye, Cy5.5. Optical imaging showed that the Cy5.5 signal increased in the infarct region 24 h after administration. Immunohistochemistry data showed that targeted delivery of SDF-1α enhanced neurogenesis and angiogenesis, but did not influence cell survival or inflammation. These observations suggest that SDF-1α-loaded pH-sensitive polymeric micelles can be used as pH-triggered targeting agents and can effectively modify the microenvironment to increase innate neurorestorative processes.     

Endothelial progenitor cells may participate in stress-induced tumour angiogenesis

Epidemiological and animal studies have suggested that chronic stress promotes tumourigenesis by promoting tumour angiogenesis. However, underlying mechanisms have not been fully elucidated. Endothelial progenitor cells (EPCs) are a group of bone marrow–derived cells that have an important function in neovascularisation of various tumour growths. In this study, chronic stress was hypothesised to increase tumour angiogenesis via sympathetic neurotransmitter-induced activation of EPCs through α1 adrenoreceptor (AR)-extracellular regulated protein kinases and β2 AR-endothelial nitric oxide synthase signal pathways. This hypothesis should be tested in several clinical and animal studies. Results may have implications on the development of new anti-tumour drugs.     

Postischemic exercise decreases neurogenesis in the adult rat dentate gyrus

Running exercise enhances neurogenesis in the normal adult and aged hippocampus. However, the effect of exercise on neurogenesis in the ischemic hippocampus is unclear. Here, we show that running exercise has different effects on ischemic and non-ischemic brain. Young (3-4-month-old) normotensive Wistar rats were used for this study. We administered bromodeoxyuridine (BrdU) to rats 7 days after the induction of transient forebrain ischemia or sham operation. BrdU-labeled cells were increased in the ischemic subgranular zone (SGZ) and granule cell layer (GCL) and double immunofluoresence showed approximately 80% of BrdU-labeled cells expressed neuronal markers. To assess the effect of running exercise on neurogenesis, BrdU-labeled cells in these regions were quantified after 1 day and 14 days. In sham-operated rats, the numbers of BrdU-labeled cells were significantly increased (2.2-fold) in the SGZ and GCL in response to running exercise. The numbers of BrdU-labeled cells were increased in response to ischemia, however, they were decreased 14 days after BrdU administration and running exercise accelerated the reduction in BrdU-labeled cells in ischemic rats. These findings suggest that running exercise has a negative effect on neurogenesis in the ischemic hippocampus. This may be important with respect to assessment of therapeutic approaches for functional recovery after stroke.     

Neuroprotective effect of Coenzyme Q10 on ischemic hemisphere in aged mice with mutations in the amyloid precursor protein

This study was designed to test whether Coenzyme Q10 (CoQ10) supplementation has neuroprotective effect in aged, double-transgenic amyloid precursor protein (APP)/presenilin 1 (PS1), single transgenic APP and PS1 mice exposed to ischemic injury of the brain. Forty-eight mice (12 each of APP/PS1, APP, PS1 and wild-type) were studied. Half of each genotype groups (n=6 per group) was treated with CoQ10 (1200 mg/kg/day) after ischemic injury and the other half with placebo. Magnetic resonance (MR) images were used to measure the volume of induced infarction (IFV), as well as the volume of the hemispheres and hippocampi. Significantly greater volumes of infarction and lesser volumes of hemisphere/hippocampus on the ischemic side were observed in APP/PS1 and APP mice than in PS1 and wild-type mice. This is consistent with amplification of the effect of ischemia in APP carriers. After 28 days of CoQ10 treatment, APP/PS1 or APP mutations have smaller infarct volumes, while the volumes of hemisphere and hippocampus on the infarcted side were larger than those treated with placebo. No differences between CoQ10- and placebo-treated groups in volumes of infarct, hemisphere and hippocampus were observed in PS1 and wild-type mice. We conclude that CoQ10 has a protective effect on the brain from infarction and atrophy induced by ischemic injury in aged and susceptible transgenic mice.     

Effects of CD11b/18 monoclonal antibody on rats with permanent middle cerebral artery occlusion.

The progression of a lesion from ischemic injury to infarct, after the permanent occlusion of a middle cerebral artery, may be influenced by the influx of leukocytes into the ischemic territory. We aimed to evaluate the effectiveness of treating rats that had permanent middle cerebral artery occlusion with a single dose of an anti-CD11b/18 monoclonal antibody injected 1 hour after the arterial occlusion. To mimic the clinical situation of patients with ischemic strokes who may be treated within 1 hour of the ischemic event, the artery remained occluded. Forty-one adult Wistar rats had permanent middle cerebral artery occlusion, and one was subjected to a sham operation. One hour later, 22 rats received CD11b/18 monoclonal antibody and an additional 20 were injected either with a nonspecific antibody (n = 10) or a buffer solution (n = 10). Experiments were terminated at intervals ranging 12 to 96 hours after the arterial occlusion. Endpoints included neurological testing, daily evaluation of body weight, counts of white blood cells in the peripheral blood, measurement of the area of pallor in the ischemic hemisphere, counts of necrotic neurons, and counts of leukocytes sequestered in the ischemic hemisphere. In experiments terminated 12 hours after the arterial occlusion (n = 4), there were fewer necrotic neurons in the group treated with the CD11b/18 monoclonal antibody compared with the two controls (P < .05), but this difference was not reflected in the neurological scores. Numbers of necrotic neurons in experiments terminated > 12 hours later were not different among the three subgroups. White blood cell counts in peripheral blood were lower in animals with arterial occlusion injected with the monoclonal antibody CD11b/18 (P < .05); numbers of leukocytes sequestered in the ischemic hemisphere were not different in the three groups. Neither changes in body weight nor in the volume of the area of pallor were significantly different among the three groups.     

Abeta(1-42) stimulates adult SVZ neurogenesis through the p75 neurotrophin receptor

The generation of amyloid-beta peptide (Aβ) and its accumulation in amyloid plaques are generally recognized as key characteristics of Alzheimer's disease. A number of reports have indicated that Aβ can regulate the proliferation of neural precursor cells and adult neurogenesis, suggesting that this may underpin the cognitive decline and compromised olfaction also associated with the condition. Here we report that Aβ_1–42 treatment both in vitro and in vivo, as well as endogenous generation of Aβ in C100 and APP/PS1 transgenic models of Alzheimer's disease, stimulate neurogenesis of young adult subventricular zone precursors. The neurogenic effect of Aβ_1–42 was found to require expression of the p75 neurotrophin receptor (p75^NTR) by the precursor cells, and activation of p75^NTR by metalloprotease cleavage. However, precursors from 12-month-old APP/PS1 mice failed to respond to Aβ_1–42. Our results suggest that overstimulation of p75^NTR-positive progenitors during early life might result in depletion of the stem cell pool and thus a more rapid decline in basal neurogenesis. This, in turn, could lead to impaired neurogenic function in later life.     

Cilostazol attenuates ischemic brain injury and enhances neurogenesis in the subventricular zone of adult mice after transient focal cerebral ischemia

Evidence suggests that neurogenesis occurs in the adult mammalian brain, and that various stimuli, for example, ischemia/hypoxia, enhance the generation of neural progenitor cells in the subventricular zone (SVZ) and their migration into the olfactory bulb. In a mouse stroke model, focal ischemia results in activation of neural progenitor cells followed by their migration into the ischemic lesion. The present study assessed the in vivo effects of cilostazol, a type 3 phosphodiesterase inhibitor known to activate the cAMP-responsive element binding protein (CREB) signaling, on neurogenesis in the ipsilateral SVZ and peri-infarct area in a mouse model of transient middle cerebral artery occlusion. Mice were divided into sham operated (n=12), vehicle- (n=18) and cilostazol-treated (n=18) groups. Sections stained for 5-bromodeoxyuridine (BrdU) and several neuronal and a glial markers were analyzed at post-ischemia days 1, 3 and 7. Cilostazol reduced brain ischemic volume (P<0.05) and induced earlier recovery of neurologic deficit (P<0.05). Cilostazol significantly increased the density of BrdU-positive newly-formed cells in the SVZ compared with the vehicle group without ischemia. Increased density of doublecortin (DCX)-positive and BrdU/DCX-double positive neural progenitor cells was noted in the ipsilateral SVZ and peri-infarct area at 3 and 7 days after focal ischemia compared with the vehicle group (P<0.05). Cilostazol increased DCX-positive phosphorylated CREB (pCREB)-expressing neural progenitor cells, and increased brain derived neurotrophic factor (BDNF)-expressing astrocytes in the ipsilateral SVZ and peri-infarct area. The results indicated that cilostazol enhanced neural progenitor cell generation in both ipsilateral SVZ and peri-infarct area through CREB-mediated signaling pathway after focal ischemia.