Pro-inflammatory microglia mainly rely on glycolysis to maintain cytokine production during ischemia, accompanied by an increase in inducible nitric oxide synthase (iNOS) and monocarboxylate transporter 1 (MCT1). The role of energy metabolism in the pro-inflammatory response of microglia is currently unclear. In this study, we tested the response of microglia in mice after cerebral ischemia and simulated an energy environment in vitro using low glucose culture medium. The research results indicate that the expression levels of iNOS and arginase 1 (ARG1) increase in the ischemic mouse brain, but the upregulation of MCT1 expression is mainly present in iNOS positive microglia. In microglia exposed to low glucose conditions, iNOS and MCT1 levels increased, while ARG1 levels decreased. Under the same conditions, knocking down MCT1 in microglia leads to a decrease in iNOS levels, while overexpression of MCT1 leads to the opposite result. The use of NF-κB inhibitors reduced the expression levels of iNOS and MCT1 in microglia. In summary, our data indicate that pyruvate maintains and enhances the NF-κB regulated pro-inflammatory response of microglia induced by low glucose.

Inflammatory bowel disease (IBD) is a chronic and recurrent gastrointestinal inflammation regulated by intricate mechanisms. Recently, prebiotics is considered as promising nutritional strategy for the prevention and treatment of IBD. Prevotella histicola (P. histicola), an emerging probiotic, possesses apparently anti-inflammatory bioactivity. However, the role and underlying mechanism of P. histicola on IBD remain unclear. Hence, we probe into the effect of P. histicola on dextran sulfate sodium (DSS)-induced colitis and clarified the potential mechanism. Our results revealed that DSS-induced colonic inflammatory response and damaged epithelial barrier in mice were attenuated by oral administration of P. histicola. Moreover, supplementary P. histicola significantly enriched short-chain fatty acid (SCFA)-producing bacteria (Lactobacillus, and Bacillus) and reduced pathogenic bacteria (Erysipelotrichaceae, Clostridium, Bacteroides) in DSS-induced colitis. Notably, In DSS-treated mice, endoplasmic reticulum stress (ERS) was persistently activated in colonic tissue. Conversely, P. histicola gavage suppressed expansion of endoplasmic reticulum, downregulated PERK-ATF4-CHOP and IRE1α-JNK pathway. In vitro, the P. histicola supernatant eliminated LPS-induced higher production of pro-inflammatory cytokines regulated by NF-κB and impairment of epithelial barrier by inhibiting IRE1α-JNK signaling in Caco-2 cell. In summary, our study indicated that P. histicola mitigated DSS-induced chronic colitis via inhibiting IRE1α-JNK pathway and NF-κB signaling. These findings provide the new insights into the promotion of gut homeostasis and the application potential of P. histicola as a prebiotic for IBD in the future.

Ischemic stroke is the main cause of death and disability, and microglia play a crucial role in the pathophysiology of hypoxic ischemic brain injury. We found that SENP3 is highly expressed in the early stages of ischemic stroke in both in vivo and in vitro mouse models, and may be related to the deSUMOylation of the key kinase MKK7 in the TLR4/p-JNK signaling pathway. Knocking down SENP3 can inhibit the deSUMOylation of MKK7, thereby inhibiting the activation of the TLR4/p-JNK signaling pathway in an in vitro stroke model. Proteomic analysis showed that SENP3 undergoes phosphorylation at the T429 site after ischemic stroke. Computer simulation predictions show a significant enhancement of the interaction between pT429-SENP3 and MKK7, which has been confirmed through experiments on the interaction of biological macromolecules (SPR). The mitochondrial metabolic abnormalities caused by energy abnormalities in the early stages of stroke provide a good explanation for the phosphorylation of SENP3. Therefore, we used the mitochondrial complex inhibitor TTFA to reverse demonstrate that the phosphorylation of SENP3 comes from the large amount of adenosine triphosphate produced by mitochondrial abnormal metabolism caused by early oxygen glucose deficiency. Finally, proteomic analysis indicates that a significant amount of oxidative phosphorylation does occur in the early stages of stroke. In summary, targeted regulation of SENP3 phosphorylation to affect the deSUMOylation of MKK7 may inhibit secondary inflammation in ischemic stroke.

The development of heat-induced antigen retrieval technologies with Tris-EDTA buffer has dramatically improved immunostaining of specific antigens for routine immunohistochemical detection (Krenacs et al., 2010) [1]. However, little evidence exists on whether heat-Induced antigen retrieval utilizing Tris-EDTA buffer can strip western blot (WB) membranes and allow sequential reprobing. Here, we serendipitously discover that-95 degrees C Tris-EDTA buffer with 0.01% Tween 20 could repeatedly strip the Nitrocellulose membranes (NC). After electroblotting, NC blots were soaked into Tris-EDTA stripping buffer (-95 degrees C, 10-25min) and we could perform at least five rounds (the following antibodies used: Vinculin, Atg7, Caspase-3, UBA5, JNK and ERK1/2) stripping in sequential chemiluminescent detections. The NC membranes also show clear western signals and background without losing transferred proteins during the reprobing process of WB. Hence, this study report additional new roles of the heat-Induced antigen retrieval Tris-EDTA buffer with 0.01% Tween 20. The method is simpler, more affordable and harmless for the nitrocellulose paper, which will be helpful for effective reprobing in western blotting applications.

In this study, we investigated the effect of neuregulin-1 (NRG1) on demyelination and neurological function in an ischemic stroke model, and further explored its neuroprotective mechanisms. Adult male ICR mice underwent photothrombotic ischemia surgery and were injected with NRG1 beginning 30 min after ischemia. Cylinder and grid walking tests were performed to evaluate the forepaw function. In addition, the effect of NRG1 on neuronal damage/death (Cresyl violet, CV), neuronal nuclei (NeuN), nestin, doublecortin (DCX), myelin basic protein (MBP), non-phosphorylated neurofilaments (SMI-32), adenomatous polyposis coli (APC), erythroblastic leuke-mia viral oncogene homolog (ErbB) 2, 4 and serine-threonine protein kinase (Akt) in cortex were evaluated using immunohistochemistry, immunofluorescence and western blot. The cylinder and grid walking tests exposed that treatment of NRG1 observably regained the forepaw function. NRG1 treatment reduced cerebral infarction, restored forepaw function, promoted proliferation and differentiation of neuron and increased oligoden-drogliogenesis. The neuroprotective effect of NRG1 is involved in its activation of PI3K/Akt signaling pathway via ErbB2, as shown by the suppression of the effect of NRG1 by the PI3K inhibitor LY294002. Our results demonstrate that NRG1 is effective in ameliorating the both acute phase neuroprotection and long-term neurological functions via resumption of neuronal proliferation and differentiation and oligodendrogliogenesis in a male mouse model of ischemic stroke.

Abstract Background Accumulating evidence indicates that intestinal microbiota not only influence development and behavior but also play important roles in the pathogenesis of neurodegenerative diseases. However, the relationships between gut bacteria and diseases of the nervous system remain to be fully explored. Microglial activation has been identified as an important factor affecting the progression of many degenerative diseases. Therefore, we aimed to investigate the effects of Prevotella histicola on neuroinflammation and associated mechanisms in an animal model of dopaminergic neuron death caused by microglia activation. Methods We used the Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) to establish an animal model of dopaminergic neuron death induced by microglia activation. LPS was injected into the mouse substantia nigra, followed by gavage with P. histicola. Results P. histicola inhibited LPS-induced microglia activation by increasing the proportion of peripheral regulatory T cells (Treg), thereby increasing the secretion of interleukin (IL)-10, reducing dopaminergic neuron damage, stimulating activation of anti-inflammatory M2 type microglia, and improving exercise capacity. Interestingly, P. histicola treatment suppressed the expression of SUMO-specific protease 3 (SENP3), which plays an important role in LPS-stimulated inflammatory TLR4 signaling. P. histicola treatment also downregulated inflammatory factors including IL-1, IL-6, IL-12, and tumor necrosis factor-alpha (TNFα). Conclusion These results suggest that P. histicola inhibits the TLR4 inflammatory signaling pathway and release of inflammatory factors by regulating the release of IL-10 from FoxP3 + Treg cells in the spleen. Our findings may provide insight into a new therapeutic avenue for attenuating the progression of degenerative diseases involving microglial activation.

目的 探讨达珀利奈[(E)-Daporinad,FK866]对急性缺血性脑卒中皮层神经炎症、胶质瘢痕增生的影响与机制.方法 实验动物分为假手术组(Sham组)、缺血损伤手术组(Vehicle组)和缺血手术后给予FK866干预组(FK866组),每组8只.尼氏染色检测小鼠大脑皮层缺血损伤程度,TUNEL染色检测神经元凋亡,圆筒试验和网格爬行试验检测小鼠运动、协调能力,免疫组织化学染色检测小鼠大脑皮层缺血部位离子化钙结合适配体分子1(ionized calcium-binding adapter molecule 1,Iba1)与胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达,免疫印迹检测小鼠大脑皮层Iba1、诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、分化簇206(cluster of differentiation 206,CD206)、GFAP、胶质瘢痕标记物磷酸蛋白聚糖(phosphacan)α和Toll/白细胞介素受体结构域的蛋白1(sterile alpha and TIR motif-containing protein 1,SARM1)的表达.结果 与Vehicle组相比,FK866组小鼠大脑皮层缺血灶面积减少,凋亡神经元细胞数量减少,小鼠的运动、协调功能增强,缺血灶部位小胶质细胞及星形胶质细胞的活化减弱,Iba1、iNOS、GFAP和phosphacan蛋白表达水平降低,CD206蛋白水平增高,SARM1的蛋白水平下降.结论 在缺血性脑卒中急性期,FK866减轻病灶处的神经元损伤并发挥神经保护作用,可能是通过降低SARM1的表达进而促进小胶质细胞向M2型极化并抑制胶质瘢痕的形成.

Although Notch signalling pathway could control the proliferation and differentiation of neural stem cells (NSCs), it is largely unknown about the effect of Notch signalling pathway on the neurogenesis of CD133-positive cells. By using the primary cultured ependymal cells and the transgenic mouse, we found that CD133 immunoreactivity was exclusively localized in the ependymal layer of ventricles; moreover, most CD133-positive cells were co-labelled with Nestin. In addition, recombination signal binding protein J (RBP-J), a key nuclear effector of Notch signalling pathway, was highly active in CD133-positive cells. CD133-positive cells can differentiate into the immature and mature neurons; in particular, the number of CD133-positive cells differentiating into the immature and mature neurons was significantly increased following the deficiency or interference of RBP-J in vivo or in vitro. By using real-time qPCR and Western blot, we found that RBP-J and Hes1 were downregulated, whereas Notch1 was upregulated in the expression levels of mRNAs and proteins following the deficiency or interference of RBP-J. These results demonstrated RBP-J deficiency promoted the proliferation and differentiation of CD133-positive cells. Therefore, we speculated that RBP-J could maintain CD133-positive cells in the characteristics of NSCs possibly by regulating Notch1/RBP-J/Hes1 pathway. It will provide a novel molecular insight into the function of RBP-J as well as facilitate a future investigation of CD133-positive cells with respect to their potential application in neurodegenerative disorder.

目的:探讨创伤性脑损伤小鼠小胶质细胞中小泛素样修饰蛋白(small ubiquitin-like modifier,SUMO)特异性蛋白酶3(SUMO-specific protease 3,SENP3)的作用及其机制.方法:体外培养小鼠小胶质细胞系BV-2并建立划痕损伤模型,模拟创伤性脑损伤时小胶质细胞的病理生理变化.以划痕的损伤程度将实验分为对照组、轻度损伤组和重度损伤组.采用CCK-8法和过氧化氢(hydrogen peroxide,H2O2)试剂盒检测各组细胞的损伤程度.利用Western blot、免疫荧光染色、RT-PCR及SENP3特异性小干扰RNA(small interfering RNA,siRNA)敲减技术检测创伤性脑损伤模型中小胶质细胞内SENP3与Toll样受体4(Toll-like receptor 4,TLR4)信号通路的关系.结果:Western blot结果显示,随着损伤程度的加重及时间的推移,SENP3的表达水平逐渐升高(P<0.05或P<0.01),且丝裂原活化蛋白激酶激酶7(mitogen-activated protein kinase kinase 7,MKK7)的去SUMO化和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)的磷酸化水平也逐渐上升(P<0.05或P<0.01).免疫荧光染色结果显示,随着创伤性脑损伤程度的加重,小胶质细胞中SENP3积累增多,且小胶质细胞主要向M1型分化,炎症因子白细胞介素1β(interleukin-1β,IL-1β)及肿瘤坏死因子α(tumor necrosis factorα,TNF-α)的mRNA及蛋白水平在损伤后均显著升高(P<0.05).用siRNA敲减SENP3后,JNK的磷酸化水平显著下降(P<0.01),且炎症因子IL-1β和TNF-α的蛋白表达水平也显著下降(P<0.05或P<0.01).结论:创伤性脑损伤后小胶质细胞内的SENP3促进了TLR4信号通路的激活及炎症因子的释放,从而促进创伤性脑损伤后神经炎症的发生和发展.

目的 探讨小泛素样修饰蛋白特异性蛋白酶3(SENP3)在光化学栓塞法缺血性脑卒中小鼠小胶质细胞中的表达变化,以及与光化学法栓塞缺血性脑卒中疾病进展的关系.方法 实验小鼠分对照组、缺血性脑卒中1d组和缺血性脑卒中7 d组(每组3只),应用Western blotting检测各组纹状体诱导型一氧化氮合酶(iNOS)、精氨酸酶1(ARG-1)和SENP3的表达和c-Jun氨基末端激酶(JNK)磷酸化水平;应用免疫荧光双标法检测小鼠纹状体小胶质细胞中iNOS和ARG-1的表达.结果 与对照组相比,缺血性脑卒中1 d组SENP3的表达与JNK的磷酸化水平均显著上升,同时M1型小胶质细胞的标志物iNOS的表达水平显著上升;缺血性脑卒中7 d组M2型小胶质细胞的标记物ARG-1的表达显著增高.纹状体小胶质细胞特异性抗体1(Iba1)与iNOS、Iba1与ARG-1的免疫荧光双标结果与免疫印迹结果一致.结论 光化学栓塞法缺血性脑卒中早期,小胶质细胞SENP3表达增加,进而影响JNK磷酸化的水平和小胶质细胞的极化,促进大脑炎症反应,参与缺血性脑卒中的疾病进展.

It has been reported that allopregnanolone (APα) promotes the neurogenesis of the neural progenitor cells (NPCs) in the subventricular zone (SVZ) and prevents the decrease of dopaminergic neurons in 6‐hydroxydopamine (6‐OHDA)‐treated mice by binding to γ‐aminobutyric acid A receptor (GABAAR) and then opening voltage‐gated L‐type Ca2+ channel, but the underlying mechanisms remain elusive. The aim of this study was to explore the possible involvement of GABAAR and calcium/calmodulin‐dependent protein kinase II delta 3 (CaMKIIδ3) in this process.

Abstract Although the ependymal cells were reported to have the characteristics of neural stem cells (NSCs), the properties of CD133-ependymal cells have not been uncovered, in particular, it is largely unknown about the effect of Notch signaling pathway on the neurogenesis of CD133-positive ependymal cells. By using the transgenic mouse and primarily cultured ependymal cells, we found that the immunoreactivity for prominin-1/CD133 was exclusively localized in the subventricular zone (SVZ) and ependymal layer of ventricles, moreover, most CD133-positive ependymal cells were co-labeled with Nestin. In addition, RBP-J, a key nuclear effector of Notch signaling pathway, was highly active in CD133-positive ependymal cells. Our results demonstrated that CD133-positive ependymal cells can differentiate into the immature and mature neurons, in particular, the number of CD133-positive ependymal cells differentiating into the immature and mature neurons was significantly increased following the deficiency or interference of RBP-J in vivo or in vitro. By using real-time qPCR and Western blot, we found that RBP-J and Hes1 were down-regulated while Notch1 was up-regulated in the expression levels of mRNAs and proteins following the deficiency or interference of RBP-J in vivo or in vitro. These results demonstrated RBP-J deficiency promoted the proliferation and differentiation of CD133-positive ependymal cells. Therefore, we speculated that RBP-J could maintain CD133-positive ependymal cells in the characteristics of NSCs possibly by regulating Notch1/RBP-J/Hes1 pathway.

Aims It has been reported that allopregnanolone (AP alpha) promotes the neurogenesis of the neural progenitor cells (NPCs) in the subventricular zone (SVZ) and prevents the decrease of dopaminergic neurons in 6-hydroxydopamine (6-OHDA)-treated mice by binding to gamma-aminobutyric acid A receptor (GABAAR) and then opening voltage-gated L-type Ca(2+)channel, but the underlying mechanisms remain elusive. The aim of this study was to explore the possible involvement of GABAAR and calcium/calmodulin-dependent protein kinase II delta 3 (CaMKII delta 3) in this process. Methods 6-OHDA-treated mice and primary cultured midbrain cells were administrated with AP alpha and GABAAR antagonist bicuculline (Bic), and the proliferation and differentiation of NPCs, the tyrosine hydroxylase (TH)-positive neurons and their fibers, the expression levels of CaMKII delta 3 and brain-derived neurotrophic factor (BDNF), and motor functions were measured using ELISA, immunohistochemical staining, real-time RT-PCR, Western blot, and behavioral test. Results Allopregnanolone significantly promoted the phosphorylation of cytoplasmic CaMKII delta 3 and its nuclear translocation by binding to GABAAR, which, in turn, increased the expression levels of BDNF. This may account for the findings that the exogenous AP alpha enhanced the proliferation and differentiation of NPCs, and ameliorated the nigrostriatal system and behavioral performance in 6-OHDA-treated mice. Conclusions Allopregnanolone may directly activate GABAAR, which, in turn, enhance the proliferation and differentiation of NPCsviaupregulating the expression levels of CaMKII delta 3, and finally contribute to the restoration of dopaminergic neurons in 6-OHDA-treated mice.

Allopregnanolone (APα), as a functional neurosteroid, exhibits the neuroprotective effect on neurodegenerative diseases such as Parkinson's disease (PD) through γ-aminobutyric acid A receptor (GABAAR), but it has not been completely understood about its molecular mechanisms. In order to investigate the neuroprotective effect of APα, as well as to clarify its possible molecular mechanisms, SH-SY5Y neuronal cell lines were incubated with 6-hydroxydopamine (6-OHDA), which has been widely used as an in vitro model for PD, along with APα alone or in combination with GABAAR antagonist (bicuculline, Bic), intracellular Ca2+ chelator (EGTA) and voltage-gated L-type Ca2+ channel blocker (Nifedipine). The viability, proliferation, and differentiation of SH-SY5Y cells, the expression levels of calmodulin (CaM), Ca2+/calmodulin-dependent protein kinase II δ3 (CaMKIIδ3), cyclin-dependent kinase-1 (CDK1) and brain-derived neurotrophic factor (BDNF), as well as the interaction between CaMKIIδ3 and CDK1 or BDNF, were detected by morphological and molecular biological methodology. Our results found that the cell viability and the number of tyrosine hydroxylase (TH), bromodeoxyuridine (BrdU) and TH/BrdU-positive cells in 6-OHDA-treated SH-SY5Y cells were significantly decreased with the concomitant reduction in the expression levels of aforementioned proteins, which were ameliorated following APα administration. In addition, Bic could further increase the number of TH or BrdU-positive cells as well as the expression levels of aforementioned proteins except for TH/BrdU-double positive cells, while EGTA and Nifedipine could attenuate the expression levels of CaM, CaMKIIδ3 and BDNF. Moreover, there existed a direct interaction between CaMKIIδ3 and CDK1 or BDNF. As a result, APα-induced an increase in the number of TH-positive SH-SY5Y cells might be mediated through GABAAR via Ca2+/CaM/CaMKIIδ3/BDNF (CDK1) signaling pathway, which would ultimately facilitate to elucidate PD pathogenesis and hold a promise as an alternative therapeutic target for PD.

Polybrominated diphenyl ethers (PBDEs) and lead (Pb) are common pollutants that co-exist in the environment. These chemicals may be associated with autism spectrum disorder (ASD), yet direct evidence is lacking. More importantly, how co-exposure of these chemicals might affect ASD has never been explored. For assessing the relationship between PBDE/Pb exposure and ASD, pregnant C57BL/6 J female mice were exposed to BDE209 (0.12 ng/day), Pb (1.2 ng/day), or a BDE209/Pb mixture from gestational day (GD) 9.5 to postnatal day (PND) 21 using ALZET osmotic pumps. Polyinosinic-polycytidylic acid (poly I:C) was included as a positive control, as its single dose injection (20 mg/kg.bw; i.p.) at mid-pregnancy (GD 12.5) produces ASD-like behaviors in mouse offspring. These ASD-like phenotypes include decreased preference for social novelty, increased marble burying behavior, and learning impairment. Similar to the poly I:C control, perinatal exposure to Pb or BDE209/Pb mixture elicited increased marble burying and learning impairment, but it had no effect on sociability. Consistent with these behavioral anomalies, Pb and BDE209/Pb co-exposure as well as poly I:C exposure increased the production of pro-inflammation cytokines interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor a (TNFa), interferon y (IFNy), and interleukin 17 A (IL-17 A) in the serum, and decreased neuronal cells in the CA1 and CA3 subregions of the hippocampus. The majority of these changes in the BDE209/Pb mixture group were due to the effect of Pb rather than BDE209. However, BDE209/Pb co exposure elicited a synergistic increase in the production of IL-4, IL-6, TNFa, IFNy, and IL-17A in the serum. BDE209 exposure alone also significantly affected spatial learning and increased the production of IL-10, TNFa, and IL-17 A in the serum of male offspring. Our work demonstrates that perinatal exposure to a low dose of Pb or the BDE209/Pb mixture, although it did not induce typical ASD-like symptoms, elicited restricted, repetitive patterns of behavior and affected learning in male offspring. In addition, the synergistic increase in the systemic inflammatory response in the BDE209/Pb co-exposure group underscores the importance of evaluating chemical mixtures in disease onset.

BACKGROUNDAmyloid-β (Aβ) accumulation plays a critical role in the pathogenesis of Alzheimer's disease (AD) lesions. Deficiency of Serotonin signaling recently has been linked to the increased Aβ level in transgenic mice and humans. In addition, tryptophan hydroxylase-2 (Tph2), a second tryptophan hydroxylase isoform, controls brain serotonin synthesis. However, it remains to be determined that whether Tph2 deficient APP/PS1mice affect the formation of Aβ plaques in vivo.METHODSBoth quantitative and qualitative immunochemistry methods, as well as Congo red staining were used to evaluate the Aβ load and astrogliosis in these animals.RESULTSwe studied alterations of cortex and hippocampus in astrocytes and senile plaques by Tph2 conditional knockout (Tph2 CKO) AD mice from 6-10 months of age. Using Congo red staining and immunostained with Aβ antibody, we showed that plaques load or plaques numbers significantly increased in Tph2 CKO experimental groups at 8 to 10 months old, compared to wild type (WT) group, respectively. Using GFAP+ astrocytes immunofluorescence method, we found that the density of GFAP+ astrocytes markedly enhanced in Tph2 CKO at 10 months. We showed Aβ plaques co-localized autophagic markers LC3 and p62. Nevertheless, we did not observe any co-localization between GFAP+ astrocytes and autophagic markers, but detected the co-localization between βIII-tubulin+ neurons and autophagic markers.CONCLUSIONOverall, our work provides the preliminary evidence in vivo that Tph2 plays a role in amyloid plaques generation.

论述多媒体题库建设与应用在组织胚胎学教学中的功能与重要意义,利用计算机系统实现组织胚胎学教学资源的整合,进一步推进多媒体网络教学的进展.同时,也介绍了多媒体题库建设的主要内容、技术方法、完成途径以及要求,总结和分析了多媒体题库建设对组织胚胎学教学中发展的重要意义与应用前景.

The animal model of Parkinson's disease (PD) plays an important role in understanding its etiology,pathogenesis and detection of new treatment regimens.The discovery of endogenous neurogenesis in the adult mammalian brain provides a new direction for the therapy of neurodegenerative diseases,such as PD,based on cellular approaches.Although a lot of attention has been focused on neurotoxin-induced endogenous neurogenesis in the brain of animal models for PD,it remains controversial whether neural stem cells migrate to the damaged brain region and promote the repopulation of reduced dopaminergic neurons in adult neurotoxic injured animals.In this paper,we review various literatures on neurogenesis in neurotoxin-induced animal models for PD,aiming to deepen the understanding of the role of neurogenesis in neurotoxicity-induced animal models for PD.

Parkinson's disease (PD) is a progressive neurological disease, one of the pathological characteristics is a gradual loss of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta (SNpc). In animals, PD-like symptoms can be induced by genetic mutations or by neurotoxins such as 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). It has been reported that deletion of autophagy-related gene 5 (Atg5) in the brain can disrupt neural function and is accompanied by the accumulation of cytoplasmic inclusions. However, the exact role of autophagy in PD etiology has not fully been asserted. In this study, we used tyrosine hydroxylase (TH)-Cre mice to generate conditional knockouts (CKO) with the specific deletion of Atg5 in mDA neurons, and found that adult Atg5 CKO mice contained ubiquitin- and p62-positive inclusions and fewer TH-positive mDA neurons compared with wild-type controls. Interestingly, MPTP-induced loss of mDA neurons was not observed in Atg5 CKO mice. Thus, Atg5-associated autophagy is required for the survival of mDA neurons, and may be involved in MPTP-induced neuronal degeneration.

Objective To investigate the impact of blocking of Notch signaling pathway (loss of expression of Notch signaling pathway) on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced damage to midbrain dopaminergic neurons.Methods Both 5-month-old TH-Cre Rbpj gene knockout mice and wild type mice (n =48) were injected intraperitoneally with MPTP to produce a Parkinson's disease (PD) animal model,then a variety of methods including behavioral test,immunohistochemistry and Western blotting were used to investigate the role of Notch signaling pathway in MPTP-induced loss of dopaminergic neurons in mouse midbrain.Results When treated with MPTP,Rbpj CKO mice exhibited better locomotor functions than wild type mice.Rbpj CKO mice were found to have fewer substantia nigra pars compacta (SNpc) neurons than wild type mice.After MPTP injection,the number of dopaminergic neurons were drastically reduced in wild type mice while in Rbpj CKO mice the number of these neurons remained virtually unchanged.Western blotting result showed that there was a significant increase in NICD-1 expression in both Rbpj CKO mice and wildtype mice,the increase was more profound in Rbpj CKO mice.Conclusion The deletion of Notch signaling pathway can lead to reduction in dopaminergic neurons,and deletion of Notch signaling pathway can reduce MPTP induced damage to dopaminergic neurons.