Diabetes can cause vascular remodelling and is associated with worse outcome after ischaemic stroke. Pioglitazone is a commonly used anti-diabetic agent. However, it is not known whether pioglitazone use before ischaemia could reduce brain ischaemic injury. Pioglitazone was administered to 5-week-old db+ or db/db mice. Cerebral vascular remodelling was examined at the age of 9 weeks. Expression of peroxisome proliferator-activated receptor-γ (PPARγ), p-PPARγ (S112 and S273), nucleotide-binding domain (NOD)-like receptor protein 3 (Nlrp3), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) was evaluated in the somatosensory cortex of mice. Neurological outcome was evaluated 24 h after brain ischaemia. Results showed that early pioglitazone treatment provided a long-lasting effect of euglycaemia but enhanced hyperlipidaemia in the db/db mice. Diabetic mice exhibited increased vascular tortuosity, narrower middle cerebral artery (MCA) width and IgG leakage in the brain. These changes were blocked by early pioglitazone treatment. In diabetic animals, PPARγ expression was reduced, and p-PPARγ at S273 but not S112, Nlrp3, IL-1β and TNF-α were increased in the somatosensory cortex. PPARγ decrease and Nlrp3 increase were mainly in the neurons of the diabetic brain, which was reversed by early pioglitazone treatment. Pioglitazone attenuated the aggravated neurological outcome after stroke in diabetic mice. But this protective effect was abolished through restoring cerebral inflammation by intracerebroventricular administration of IL-1β and TNF-α in pioglitazone-treated diabetic mice before MCAO. In summary, early pioglitazone treatment attenuates cerebral vascular remodelling and ischaemic brain injury possibly via blocking chronic neuroinflammation in the db/db mice.

目的 观察单唾液酸四己糖神经节苷脂(GM1)对急性低压氧后基质金属蛋白酶9(MMP9)表达的影响,探讨MMP9在GM1预防低压氧脑水肿中可能的机制.方法 24只雄性C57BL/6小鼠随机分成4组(n=6):分别为对照(control)组、急性低压氧(HH)组、GM1治疗(GM1+HH)组、单纯给药(GM1)组.control组:置于低压氧舱外的常氧舱内;HH组:置于6000m海拔模拟舱内24 h;HH +GM1组:连续腹腔注射GM1 3 d(30 mg/kg),最后一次给药后30 min行急性低压氧处理,方法同HH组;GM1组:前期GM1处理同HH+ GM1组,后期同control组处理.小鼠在急性低压氧处理24 h后应用免疫荧光和Western blot检测MMP9蛋白表达水平,通过湿重比和伊文思蓝定量评价脑水肿程度.结果 GM1降低急性低压氧24 h后血脑屏障损伤,减少湿重比(P＜0.05)和伊文思蓝渗出量(P＜0.05),并抑制MMP9表达上调(P＜0.05),减弱星形胶质细胞MMP9荧光强度.结论 GM1抑制MMP9表达上调,可能参与其预防急性低压氧脑水肿的机制中.

Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.

The carotid body (CB) is a complex sensory organ that functions to sense homeostatic O2 in the blood. Previous studies have shown that CBs express interleukin (IL)-1 receptor type I and that the chemosensitivity of CBs is increased following stimulation with pro-inflammatory cytokines. However, the effects of pro-inflammatory cytokines, such as IL-1β, on the neurogenesis of CB are unclear. Thus, in this study, we aimed to assess the effects of IL-1β and intermittent hypobaric hypoxia (IHH) plus IL-1β on the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, tyrosine hydroxylase (TH) and the expression of nestin, a well-established stem cell marker in the nervous system. The results showed that TH, nestin expression and ERK1/2 phosphorylation were increased in the rat CB following intraperitoneal injection of IL-1β. Moreover, IL-1β had additive effects on IHH. These results suggested that the plasticity of CB was increased following treatment with IL-1β and that ERK1/2 may be involved in neurogenic signaling in CBs.

五羟色胺(5-hydroxytryptamine,5-HT)又称为血清素(serotonin)广泛存在于机体多种组织.神经系统内的五羟色胺属于单胺类神经递质,与很多生理功能有关,参与对摄食、性行为、神经内分泌、疼痛感知、学习记忆和情绪、睡眠-觉醒等生理过程的调控.新近基于电生理、神经化学、分子生物学和神经药理学研究方法发现,五羟色胺和睡眠觉醒过程特别是觉醒过程密切相关,在促进觉醒、抑制快动眼睡眠方面有重要作用.本文介绍了五羟色胺在睡眠-觉醒周期中作用研究的最新进展.

Background Adiponectin,an adipokine secreted by different adipocytes,has been known to play pivotal roles in metabolisms including insulin sensitization,oxidation of glucose and lipids.Recently,it has been reported that adiponectin can also attenuate the process of atherosclerosis,decrease the inflammatory response,protect myocardia against ischemic reperfusion injury,and provide neuroprotection.Objective To review the related clinical studies of adiponection as a factor to assess the risk and the prognosis of ischemic stroke and basic studies about the mechanism of exogenous adiponectin induced neuroprotection against ischemic stroke injury.Content In present review,we described the recent advances in the relationship between serum adiponectin and occurrence of ischemic stroke in clinic trials and the mechanism of neuroprotection induced by supplement of adiponectin.Trend Mounting clinical studies indicate that low level of serum adiponectin is associated with high incidence and poor outcomc of ischemic stroke.Furthermore,some basic researches also demonstrate the neuroprotective effects of exogenous adipokine.

目的:观察慢性低压性缺氧和/或重组鼠白介素-1β(rmIL-1β)刺激对大鼠颈动脉体(carotid body,CB)中酪氨酸羟化酶(tyrosine hydroxylase,TH)表达的影响.方法:雄性SD大鼠分为8组,分别为缺氧刺激0、1、2、3周组和缺氧0、1、2、3周的同时伴rmIL-1β刺激组.对CB进行免疫组化染色,并用western blot法对TH进行半定量分析.结果:相对于缺氧0周组,缺氧1周、缺氧2周和缺氧3周组大鼠CB中TH的含量明显增加.相对于正常大鼠,rmIL-1β刺激引起大鼠CB中TH表达量增加.相对于单纯给予缺氧1周和缺氧2周,缺氧1周和缺氧2周同时给予rmIL-1β刺激后引起大鼠CB中TH表达量的增加.结论:慢性缺氧和rmIL-1β刺激均可致颈动脉体TH上调,慢性缺氧伴rmIL-1β刺激比单纯缺氧刺激可引起TH更显著的增加.这个结果提示慢性缺氧或促炎性细胞因子IL-1β刺激不仅能够分别促进颈动脉体中儿茶酚胺类物质的合成,而且IL-1β刺激可以促进慢性缺氧时颈动脉体中儿茶酚胺类物质的合成.这说明促炎性细胞因子可能对大鼠颈动脉体的慢性缺氧感受发挥调节作用.

Objective: To observe the effects of chronic hypoxia and systemic administration of recombinant murine interleukin-1 beta(rmIL-1β) on the expression of phosphorylated extracelluar signal-regulated kinase1/2(p-ERK1/2) in the rat carotid body(CB).Methods: Adult male Sprague-Dawley rats were divided into 8 groups: chronic intermittent hypobaric oxygen stimulation for 0,1,2 and 3 weeks groups,and chronic intermittent hypobaric oxygen exposure for 0,1,2,and 3 weeks paired with rmIL-1β injection groups.Immunohistochemistry and Western Blot techniques were employed to observe expressions of p-ERK1/2 in the CB of all rats.Results: The expression of p-ERK1/2 in the CB of the rats exposed to hypoxia for 2 weeks or 3 weeks were up-regulated compared with that in group exposed to hypoxia for 0 week.The expression of p-ERK1/2 in the CB of the rats exposed to hypoxia plus rmIL-1β injection were up-regulated compared with that in group only exposed to hypoxia.Conclusion: Both chronic hypoxia stimulation and rmIL-1β can up-regulate the expression of p-ERK1/2 in the CB;the combination of hypoxia and rmIL-1β stimulation can significantly enhance the expression of p-ERK1/2 in CB compared with single treatment by hypoxia or rmIL-1β.

Objective: To study the expression of tumor necrosis factor receptor type Ⅰ( TNFR-Ⅰ) in the rat carotid body( CB),and the effect of TNF-α on intracellular Ca2 +( [Ca2+]i) level in the glomus cells of the rat CB. Methods: Western Blot and double immunofluorescent double staining methods were used to investigate the expression of TNFR-Ⅰ in the rat CB. Calcium imaging was used to observe the effect of TNF-α on [Ca2+]i level in the glomus cells of the rat CB. Results: The result of Western Blot shwed that TNFR-Ⅰ protein band appeared at 55 kD,consistent with the molecular weight of the receptor. The result of double immunofluorescent staining showed that TNFR-Ⅰ was expressed in the CB glomus cells. The result of calcium imaging showed that extracellular application of TNF-α induced a rise in [Ca2+]i level in the cultured glomus cells of the rat CB. Conclusion: TNFR-Ⅰ is strongly expressed in the glomus cells of the rat CB,and the glomus cells can sense the stimulation of proinflammatory cytokine TNF-α.

Objective: To investigate the effect of chronic hypoxia on the expression of Wnt-1 and β-catenin in the rat carotid body(CB).Methods: Forty male SD rats were randomly divided into 5 groups: the control group,chronic intermittent hypobaric oxygen stimulation for 1,2,3 and 4w groups.The expression of Wnt-1 and β-catenin in rat carotid body were detected by Western Blot.Results: There was no significant difference for the expression of Wnt-1 in rat CB between the hypoxia 3 w group and the hypoxia 4 w group(P > 0.05).However,there was significant difference for the expression of Wnt-1 in rat CB between the other groups(P<0.05).The expression of β-catenin in the CB of the rats exposed to hypoxia for 3 w was up-regulated compared with that in the control group(P<0.05).Conclusion: The results suggest that Wnt/β-catenin signal pathway may be involved in chronic hypoxia-induced carotid body stem cell proliferation and differentiation processes.

Objective:To investigate the effect of amifostine on the ischemia-reperfusion injury in neuron-like PC12 cells.Methods:PC12 cells were exposed to oxygen-glucose deprivation(OGD) for 4h followed by 20h reoxygenation.Various doses of amfostine were added into the medium.Cell morphological changes were observed under microscopy and cell viability and integrity were detected by MTT and LDH techniques.Cell apoptosis was detected by Tunel staining and flow cytometry.Results:High concentration of amfostine could inhibite PC12 cell viability(P0.05).Amifostine attenuated the cell viability loss(P0.05) and LDH leakage(P0.05) induced by OGD,protected PC12 cell morphology and decreased cell apoptosis(P0.05).Conclusion:The amifostine had a protective effect on the OGD-induced ischemia reperfusion in neuronal cells.

BACKGROUND:Signal transducer and activator of transcription 3 (STAT3) activation in ischemic brain has been verified. However, the mechanism and the role of STAT3 activation after cerebral ischemia-reperfusion are poorly elucidated. In the present study, we sought to test the hypothesis that STAT3 activation after cerebral ischemia-reperfusion was related to reactive oxygen species (ROS) production. METHODS:Adult male Sprague-Dawley rats were subjected to focal cerebral ischemia induced by middle cerebral artery occlusion. STAT3 activation was evaluated by immunohistochemistry and Western blotting. Rats were subjected to permanent ischemia or ischemia-reperfusion to clarify the temporal profile of STAT3 activation. The role of ROS in inducing STAT3 activation was assessed by administration of the ROS scavenger dimethylthiourea (DMTU). The effects of DMTU and the STAT3 activation inhibitor AG490 administration on brain ischemic injuries were evaluated by neurologic behavior scores and brain infarct volumes. RESULTS:The activation of STAT3 after middle cerebral artery occlusion was significantly increased within peri-ischemia neurons and astrocytes. STAT3 activation mainly occurred in the reperfusion phase rather than in the ischemia phase. In addition, DMTU suppressed STAT3 activation in a dose-dependent manner, indicating that STAT3 activation may be a subsequent event after ROS production. DMTU and AG490 significantly reduced infarct sizes and improved neurologic outcomes. CONCLUSION:In comparison with ischemia, reperfusion is a more powerful stimulus for STAT3 activation. ROS scavenging is closely correlated with an inhibition of STAT3 activation. Neuroprotective effects are achieved through ROS scavenging and down-regulation of STAT3 activation.

Sertraline is one of the most commonly used antidepressants in clinic. Although it is well accepted that sertraline exerts its action through inhibition of the reuptake of serotonin at presynaptic site in the brain, its effect on the neural stem cells (NSCs) has not been well elucidated. In this study, we utilized NSCs separated from the hippocampus of fetal rat to investigate the effect of sertraline on the proliferation and differentiation of NSCs. The study demonstrated that sertraline had no effect on NSCs proliferation but it significantly promoted NSCs to differentiate into serotoninergic neurons other than glia cells. Furthermore, we found that sertraline protected NSCs against the lipopolysaccharide-induced cellular damage. These data indicate that sertraline can promote neurogenesis and protect the viability of neural stem cells.

Objective To investigate the effect of immunoglobulin G (IgG) extravasated from blood circulation on the expression of toll-like receptor 4 (TLR4) induced by peripheral lipopolysaccharide (LPS) in rat brain. Methods The rats were divided into four groups in random, 5 rats in each. Group one received LPS 100μg/kg by intraperitoneal administration, normal saline was given by intravenous injection 6 hours later; group two was injected with adrenalin (AD) 15μg/kg intravenously; group three was treated with LPS intraperitoneally, AD was injected 6 hours later; group four was injected normal saline intravenously as control. For all groups, the animals were sacrificed 30 min after the last injection, and the brains were taken for investigation of the TLR4 expressions by immunofluorescence staining and RT-PCR. Result Immunofluorescence staining showed that IgG immunoreactive product was patch-like, distributed in the brain parenchyma in all the animals that received AD. In the LPS+normal saline group, IgG was found merely around the blood vessels. Meanwhile, in LPS+AD animals, TLR4 immunoreactive product coexisted with microglia marker Iba-1 within the IgG extravasated area. The double-labeled cells dispersed in the brain parenchyma and near to the cerebral vessels. In the LPS+saline group, TLR4 positive cells were endothelial-like. RT-PCR results indicated that the expression level of TLR4 in the LPS+AD group were significantly higher than that in the LPS+saline group or AD group or the saline control (P<0.01). Conclusion Extravasated circulating IgG may enhance the TLR4 expression in the rat brain induced by peripheral LPS.

Choroidal neovascularization (CNV) is a common cause of severe and irreversible visual loss; however, the treatment of CNV has been hindered by its complex and poorly understood pathogenesis. It has been postulated that bone marrow (BM)-derived cells (BMCs) contribute to CNV, but little is known about the role of mesenchymal stem cells (MSCs) in CNV and their therapeutic potential for CNV treatment. We found that BM-derived MSCs transplanted by intravenous injection into laser-induced CNV mouse models were specifically recruited into CNV lesions, where they differentiated into multiple cell types and participated in the development of neovascularization, without stagnation in other organs. By taking advantage of this recruitment potential, engineered MSCs were used to produce the antiangiogenic pigment epithelial-derived factor (PEDF) at the CNV sites, thereby inhibiting the growth of CNVs and stimulating regressive features. Further studies indicated that the effect may be mediated, at least partly, by retinal pigment epithelial (RPE) cells, which function as important regulators for CNV development. These results suggest that MSCs contribute to CNV and could serve as delivery vehicles of antiangiogenic agents for the treatment of a range of CNV-associated diseases.

Background The chronic ocular hypertension will cause the damage of retinal ganglion cells(RGCs).Research showed that effect of pigment epithelium-derived factor (PEDF) has the protective effect on the nerve system.ObjectiveThe present study was to investigate the effect of PEDF on the RGCs in chronic intraocular pressure(IOP) eyes.MethodsThe chronic ocular hypertension models were created in 24 eyes of 24 female adult SPF Sprague Dawley rats by cauterizing the episcleral veins to elevate the IOP to 31 mmHg.The another 12 matched rats only incised the bulber conjunctiva without cauterizing the episcleral veins as sham group.2 μL (0.05 g/L) homologous recombination rat PEDF was intravitreously injected in 12 model rats and 12 sham rats after removal of 2 μL vitreous body,and the equal amount of deionized water was intravitreously injected in another 12 model rats.The animals were sacrificed and the eye balls were cut with cryostat on and 14 days after injection,and the TUNEL and Fluoro-Jade(FJ) staining protocols were carried out to detect the apoptotic cells and degenerative neurons in the retina.The experiment followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.ResultsThe IOP was obviously increased in all of the model rats in comparison with the sham operation group(P0.05).No significant difference was seen in IOP between 3 days and 14 days in each group(P0.05).The rate of TUNEL-positive cells was significantly increased in model+PEDF group and model+deionized water group in comparison with sham+PEDF group(both P0.05),and evidently decrease value was found in the rate of TUNEL-positive cells between model+PEDF group and model+ deionized water group(P0.05) or between model+PEDF 3-day group and model+ PEDF 14-day group(P0.05).The rate of FJ-positive cells in retina followed the same pattern of TUNEL assay.ConclusionIntravitreal administration of the PEDF has the protective effect on the ocular hypertension-damage of RGCs by reducing the apoptosis and degeneration of neuron.

Although abundant evidence indicates mutual regulation between the immune and the central nervous systems, how the immune signals are transmitted to the brain is still an unresolved question. In a previous study we found strong expression of proinflammatory cytokine receptors, including interleukin (IL)-1 receptor I and IL-6 receptor a in the rat carotid body (CB), a well-known arterial chemoreceptor that senses a variety of chemostimuli in the arterial blood. We demonstrated that IL-1 stimulation increases intracellular calcium ([Ca2+](i)) in CB glomus cells, releases ATP, and increases the discharge rate in carotid sinus nerve. To explore the effect of IL-6 on CB, here we examine the effect of IL-6 on [Ca2+](i) and catecholamine (CA) secretion in rat CB glomus cells. Calcium imaging showed that extracellular application of IL-6 induced a rise in [Ca2+](i) in cultured glomus cells. Amperometry showed that local application of IL-6 evoked CA release from glomus cells. Furthermore, the CA secretory response to IL-6 was blocked by 200 mu M Cd2+, a well-known Ca2+ channel blocker. Our experiments provide further evidence for the responsiveness of the CB to proinflammatory cytokines and indicate that the CB might play a role in inflammation sensing and transmission of such information to the brain. (C) 2009 Wiley-Liss, Inc.

AIM: To investigate the characteristics of Ets-1 and VEGF expression and distribution in the experimental diabetic rat retina.METHODS: Diabetes was induced by intraperitoneal injection of streptozotocin (STZ). At 4 weeks after STZ-injection, animals were sacrificed. Total proteins were isolated from retinas of experimental eyes and control eyes and assessed by Western blot analysis. Frozen cross sections of eyeballs with 14 mu m thickness were used to perform double immunofluorescence staining with anti-Ets-1 and anti-VEGF antibodies.RESULTS: Both Ets-1 and VEGF expression were up-regulated in the diabetic retina, the distribution of Ets-1 and VEGF was identical to each other, and the two proteins were almost localized in all retinal layers.CONCLUSION: Ets-1 may contribute to the pathologic progress of the diabetic retina induced by VEGF.

AIM: To determine the involvement of Ets-1 in the pathological progress of the experimental diabetic retina.METHODS: Diabetes was induced by intraperitoneal injection of STZ Total RNA and total proteins were isolated from retinas of experimental and control eyes at 4 weeks after STZ-injection and were assessed by Northern blot analysis and Western blot analysis, respectively.RESULTS: Expression of both Ets-1 mRNA and Ets-1 protein was significantly increased in the experimental diabetic rat's retina after STZ-injection compared with the control group (P<0.001).CONCLUSION: Our results indicate that Ets-1 is involved in the pathological progress of experimental diabetic retina. Further studies should be conducted to focus on the relationship between Ets-1 and VEGF in the diabetic retina.