The original version of this article contained an error.In the original file of Fig. 4g, the loading controls were accidentally mirror-image changed.The loading controls of Fig. 4g should be the same as the loading controls of Fig. 3c, because in the western blotting experiment, the two proteins came from the same piece of separation glue and shared the same loading controls.
Abstract Running exercise was shown to have a positive effect on depressive-like symptoms in many studies, but the underlying mechanism of running exercise in the treatment of depression has not been determined. Parvalbumin-positive interneurons (PV + interneurons), a main subtype of GABA neurons, were shown to be decreased in the brain during the depression. PGC-1α, a molecule that is strongly related to running exercise, was shown to regulate PV + interneurons. In the present study, we found that running exercise increased the expression of PGC-1α in the hippocampus of depressed mice. Adult male mice with PGC-1α gene silencing in the hippocampus ran on a treadmill for 4 weeks. Then, depression-like behavior was evaluated by the behavioral tests, and the PV + interneurons in the hippocampus were investigated. We found that running exercise could not improve depressive-like symptoms or increase the gene expression of PV because of the lack of PGC-1α in the hippocampus. Moreover, a lack of PGC-1α in the hippocampus decreased the number and activity of PV + interneurons in the CA3 subfield of the hippocampus, and running exercise could not reverse the pathological changes because of the lack of PGC-1α. The present study demonstrated that running exercise regulates PV + interneurons through PGC-1α in the hippocampus of mice to reverse depressive-like behaviors. These data indicated that hippocampal PGC-1α-mediated positive effects on parvalbumin interneurons are required for the antidepressant actions of running exercise. Our results will help elucidate the antidepressant mechanism of running exercise and identify new targets for antidepressant treatment.
To investigate the effect of prostaglandin E2 recoptor 4 antagonist (EP4A) on the self-renewal ability of human CD34+ cells and its mechamism.The peripheral blood hematopoietic stem cell of 20 healthy donors received the G-CSF-mobilization were collected, then the human CD34+ cells were sorted out by MACS microbead kit. The human CD34+ cells were treated with DMSO (control group), EP4A (EP4A group) and EP4A+EP4A antagonist (EP4A+EP4A group) for 72 hours. The differential genes and pathways related with CD34+ cell stemness were detected by Thermogram and Pathway enrichment analysis. and then the expression levels of protein and gene (β-catenin, Nanog, Oct4, Sox2, Stat3, AKT, P38) were detected by qRT-PCR and Western blot respectively.EP4A could elevate the mRNA and protein expression of β-catenin, Nanog, Oct4, Sox2, in comparison with control group, however, mRNA and protein expression of STAT3, AKT, P38 were not changed. When human CD34+ cell were cultured with EP4A+XAV939 it was found that the mRNA and protein expression of β-catenin was downregulated, moreover the mRNA and protein expression of Nanog, Oct4, Sox2 were reduced.EP4A can upregulate stemness factors-β-catenin, Nanog, Oct4 and Sox2 in human CD34+ cell in vitro, but not STAT3, AKT and P38.EP4A对人CD34+细胞干性因子表达的影响.探讨前列腺素E2特异性受体激动剂4（EP4A）增强人CD34+细胞干性因子表达的机制.收集中山大学附属第一医院血液科20例健康供者经G-CSF动员后的外周血造血干细胞采集物，采用免疫磁珠法分选出人CD34+细胞。以DMSO作对照，分别用EP4A、EP4A + EP4A拮抗剂（EP4AA）作用人CD34+细胞72 h后，应用热图和Pathway富集分析检测与CD34+细胞干性相关的差异基因和通路；再用qRT-PCR和Western blot检测不同组别细胞中通路蛋白和差异基因的mRNA及蛋白（β-catenin、Nanog、Oct4、Sox2、Stat3、AKT、P38）表达水平.与对照组相比，EP4A组人CD34+细胞中β-catenin、Nanog、Oct4及Sox2 mRNA及其蛋白的表达均增高，而STAT3、AKT、P38 mRNA及其蛋白的表达无变化； EP4A与EP4AA（XAV939）共同作用人CD34+细胞时，人CD34+细胞β-catenin表达水平明显降低，并且Nanog、Oct4及Sox2基因及蛋白表达相应减少.EP4A可增加人CD34+细胞干性因子（β-catenin、Nanog、Oct4和Sox2）表达，而不能增加STAT3、AKT、P38表达.
The cause of Alzheimer's disease (AD) could be ascribed to the progressive loss of functional neurons in the brain, and hence, agents with neuroprotection and neurite outgrowth-promoting activities that allow for the replacement of lost neurons may have significant therapeutic value. In the current study, the neuroprotective and the neurite outgrowth-promoting activities and molecular mechanisms of bis(propyl)-cognitin (B3C), a multifunctional anti-AD dimer, were investigated. Briefly, B3C (24 h pretreatment) fully protected against glutamate-induced neuronal death in primary cerebellar granule neurons with an IC50 value of 0.08 μM. The neuroprotection of B3C could be abrogated by methyllycaconitine, a specific antagonist of alpha7-nicotinic acetylcholine receptor (α7-nAChR). In addition, B3C significantly promoted neurite outgrowth in both PC12 cells and primary cortical neurons, as evidenced by the increase in the percentage of cells with extended neurites as well as the up-regulation of neuronal markers growth-associated protein-43 and β-III-tubulin. Furthermore, B3C rapidly upregulated the phosphorylation of extracellular signal-regulated kinase (ERK), a critical signaling molecule in neurite outgrowth that is downstream of the α7-nAChR signal pathway. Specific inhibitors of ERK and α7-nAChR, but not those of p38 mitogen-activated protein kinase and c-Jun NH(2)-terminal kinase, blocked the neurite outgrowth as well as ERK activation in PC12 cells induced by B3C. Most importantly, genetic depletion of α7-nAChR significantly abolished B3C-induced neurite outgrowth in PC12 cells. Taken together, our results suggest that B3C provided neuroprotection and neurite outgrowth-promoting activities through the activation of α7-nAChR, which offers a novel molecular insight into the potential application of B3C in AD treatment.
The effect of propofol on proliferation of adult neural stem cells (ANSCs) is unclear. We investigated the effect of propofol on cultured rat ANSCs and the underlying molecular mechanisms, especially the role of activated cAMP response element binding protein (CREB).Rat ANSCs were treated with propofol at concentrations of 0 (control), 10, 50, or 100 μM, or with a DMSO vehicle. The cell viability was checked by cell counting and MTT assay. The proportions of BrdU-positive cells and pyknotic nuclei were also checked. Caspase activity was measured by a colorimetric assay. Cytoplasmic [Ca] were determined with Fura2-AM. The expression of CREB and phospho-CREB in cells was examined by immunostaining and Western blot. The role of p-CREB in cell proliferation was confirmed by using KN93, an inhibitor of p-CREB formation.Propofol promoted the proliferation of ANSCs (P<0.01) and increased the proportion of BrdU-positive cells (P<0.01). Cell death was maintained at a low level (P=0.0691) and inhibition of caspase-3 activity with propofol was not significant (P=0.0839). Propofol elevated the cytoplasmic-free calcium concentrations in ANSCs (P=0.0057). CREB and phospho-CREB were generally expressed in ANSCs with or without application of propofol. Propofol upregulated the phosphorylation level of CREB in ANSCs (P=0.0074). Application of KN93 diminished the proliferative effects of propofol and p-CREB levels (P<0.01) without disturbance of intracellular [Ca] (P=0.0722).Propofol acts partly through a Ca-mediated pathway to enhance CREB phosphorylation. We believe this mechanism promotes the in vitro proliferation of ANSCs.
Iron deposition is present in main lesion areas in the brains of patients with Parkinson's disease (PD) and an abnormal iron content may be associated with dopaminergic neuronal cytotoxicity and degeneration in the substantia nigra of the midbrain. However, the cause of iron deposition and its role in the pathological process of PD are unclear. In the present study, we investigated the effects of the nasal mucosal delivery of synthetic human α-synuclein (α-syn) preformed fibrils (PFFs) on the pathogenesis of PD in Macaca fascicularis. We detected that iron deposition was clearly increased in a time-dependent manner from 1 to 17 months in the substantia nigra and globus pallidus, highly contrasting to other brain regions after treatments with α-syn PFFs. At the cellular level, the iron deposits were specifically localized in microglia but not in dopaminergic neurons, nor in other types of glial cells in the substantia nigra, whereas the expression of transferrin (TF), TF receptor 1 (TFR1), TF receptor 2 (TFR2), and ferroportin (FPn) was increased in dopaminergic neurons. Furthermore, no clear dopaminergic neuron loss was observed in the substantia nigra, but with decreased immunoreactivity of tyrosine hydroxylase (TH) and appearance of axonal swelling in the putamen. The brain region-enriched and cell-type-dependent iron localizations indicate that the intranasal α-syn PFFs treatment-induced iron depositions in microglia in the substantia nigra may appear as an early cellular response that may initiate neuroinflammation in the dopaminergic system before cell death occurs. Our data suggest that the inhibition of iron deposition may be a potential approach for the early prevention and treatment of PD.
Running exercise has been shown to relieve symptoms of depression, but the mechanisms underlying the antidepressant effects are unclear. Microglia and concomitant dysregulated neuroinflammation play a pivotal role in the pathogenesis of depression. However, the effects of running exercise on hippocampal neuroinflammation and the number and activation of microglia in depression have not been studied. In this study, rats were subjected to chronic unpredictable stress (CUS) for 5 weeks followed by treadmill running for 6 weeks. The depressive-like symptoms of the rats were assessed with a sucrose preference test (SPT). Immunohistochemistry and stereology were performed to quantify the total number of ionized calcium-binding adapter molecule 1 (Iba1)+ microglia, and immunofluorescence was used to quantify the density of Iba1+/cluster of differentiation 68 (CD68)+ in subregions of the hippocampus. The levels of proinflammatory cytokines in the hippocampus were measured by qRT-PCR and ELISA. The results showed that running exercise reversed the decreased sucrose preference of rats with CUS-induced depression. In addition, CUS increased the number of hippocampal microglia and microglial activation in rats, but running exercise attenuated the CUS-induced increases in the number of microglia in the hippocampus and microglial activation in the dentate gyrus (DG) of the hippocampus. Furthermore, CUS significantly increased the hippocampal levels of inflammatory factors, and the increases in inflammatory factors in the hippocampus were suppressed by running exercise. These results suggest that the antidepressant effects of exercise may be mediated by reducing the number of microglia and inhibiting microglial activation and neuroinflammation in the hippocampus.
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