microRNA Profiling of Amniotic Fluid: Evidence of Synergy of microRNAs in Fetal Development.

Amniotic fluid (AF) continuously exchanges molecules with the fetus, playing critical roles in fetal development especially via its complex components. Among these components, microRNAs are thought to be transferred between cells loaded in microvesicles. However, the functions of AF microRNAs remain unknown. To date, few studies have examined microRNAs in amniotic fluid. In this study, we employed miRCURY Locked Nucleotide Acid arrays to profile the dynamic expression of microRNAs in AF from mice on embryonic days E13, E15, and E17. At these times, 233 microRNAs were differentially expressed (p< 0.01), accounting for 23% of the total Mus musculus microRNAs. These differentially-expressed microRNAs were divided into two distinct groups based on their expression patterns. Gene ontology analysis showed that the intersectional target genes of these differentially-expressed microRNAs were mainly distributed in synapse, synaptosome, cell projection, and cytoskeleton. Pathway analysis revealed that the target genes of the two groups of microRNAs were synergistically enriched in axon guidance, focal adhesion, and MAPK signaling pathways. MicroRNA-mRNA network analysis and gene- mapping showed that these microRNAs synergistically regulated cell motility, cell proliferation and differentiation, and especially the axon guidance process. Cancer pathways associated with growth and proliferation were also enriched in AF. Taken together, the results of this study are the first to show the functions of microRNAs in AF during fetal development, providing novel insights into interpreting the roles of AF microRNAs in fetal development.

Formaldehyde exposure alters miRNA expression profiles in the olfactory bulb.

It has been reported that inhaling formaldehyde (FA) causes damage to the central nervous system. However, it is unclear whether FA can disturb the function of the olfactory bulb. Using a microarray, we found that FA inhalation altered the miRNA expression profile. Functional enrichment analysis of the predicted targets of the changed miRNA showed that the enrichment canonical pathways and networks associated with cancer and transcriptional regulation. FA exposure disrupts miRNA expression profiles within the olfactory bulb.

17ß-estradiol protects human eyelid-derived adipose stem cells against cytotoxicity and increases transplanted cell survival in spinal cord injury.

Stem cell transplantation represents a promising strategy for the repair of spinal cord injury (SCI). However, the low survival rate of the grafted cells is a major obstacle hindering clinical success because of ongoing secondary injury processes, which includes excitotoxicity, inflammation and oxidative stress. Previous studies have shown that 17b-estradiol (E2) protects several cell types against cytotoxicity. Thus, we examined the effects of E2 on the viability of human eyelid adipose-derived stem cells (hEASCs) in vitro with hydrogen peroxide (H2O2)-induced cell model and in vivo within a rat SCI model. Our results showed that E2 protected hEASCs against H2O2-induced cell death in vitro, and enhanced the survival of grafted hEASCs in vivo by reducing apoptosis. Additionally, E2 also enhanced the secretion of growth factors by hEASCs, thereby making the local microenvironment more conducive for tissue regeneration. Overall, E2 administration enhanced the therapeutic efficacy of hEASCs transplantation and facilitated motor function recovery after SCI. Hence, E2 administration may be an intervention of choice for enhancing survival of transplanted hEASCs after SCI.

C16 peptide shown to prevent leukocyte infiltration and alleviate detrimental inflammation in acute allergic encephalomyelitis model.

Integrins are important adhesion receptors for leukocytes binding to endothelial cellular adhesion molecules. Previous studies have suggested that blocking relevant integrins might prevent leukocyte infiltration and suppress clinical and pathological features of neuroinflammatory disease. Experimental autoimmune encephalomyelitis (EAE), a rodent model of Multiple sclerosis (MS), is characterized by chronic inflammatory disorder of the central nervous system in which circulating leukocytes enter the brain and spinal cord leading to inflammation, myelin damage and subsequent paralysis. To prove this hypothesis and explore a promising application for MS treatment, the effects of C16, an ανß3 integrin-binding peptide, were tested in vitro and in vivo by transendothelial assay, electron microscopy observation, multiple histological and immunohistochemical staining. The results showed C16 inhibited transendothelial migration of the C8166-CD4 lymphoblast cells, and alleviated extensive spinal cord and brain infiltration of leukocytes and macrophages in the EAE model. Furthermore, a significant amelioration of astrogliosis and a dramatic decrease in demyelination and axonal loss were observed in C16 treated animals. The attenuating inflammatory progression may improve the regional environment and trigger further neuroprotective effects on myelin and axons, all this suggests that C16 peptide may be a promising therapeutic agent for multiple sclerosis.

The alteration of 5-HT(2A) and 5-HT(2C) receptors is involved in neuronal apoptosis of goldfish cerebellum following traumatic experience.

5-HT receptor changes remain controversial in posttraumatic stress disorder (PTSD) models. This study looks at the relationship between traumatic injuries and the alterations in 5-HT(2A) and 5-HT(2C) receptors in the goldfish brain. The effect of treatment with doxepin and fluoxetine, known to be selective serotonin reuptake inhibitor (SSRI) antidepressants, on 5-HT receptor expression in goldfish with fin ablation was also investigated. We demonstrated that fin ablation induced anxiety-like behavioural alterations and significant up-regulation of c-fos expression in goldfish cerebellum. The behavioural alterations correlated well with an increased expression of 5-HT(2A) receptors in the cerebellum of the fish with traumatic injury. An increase in the number of apoptotic cells and a higher caspase-8 protein level was present in the brains of goldfish with fin ablation compared to the control. Our findings suggest that neuronal apoptosis occured in the cerebellum as a result of fin ablation and may be related to the alterations of 5-HT(2A) and 5-HT(2C) levels and that the beneficial clinical effects of doxepin/fluoxetine treatment are due to the down-regulation of 5-HT(2A) and up-regulation of 5-HT(2C) receptors in the brain.

The miR-124 regulates the expression of BACE1/ß-secretase correlated with cell death in Alzheimer's disease.

The role of miR-124 on the expression of ß-site APP cleaving enzyme 1 (BACE1), an important cleavager of amyloid precursor protein that plays a pivotal role in the ß-amyloid production, was studied in this paper using cellular models for Alzheimer' disease (AD) of cultured PC12 cell lines and primary cultured hippocampal neurons. The aim of the present study was to uncover novel potential miR-124 targets and shed light on its function in the cellular AD model. MiR-124 expression was steadily altered when its mimic and inhibitor were transfected in vitro. The results showed the expression of BACE1, one of the potential functional downstream targets of miR-124, was well correlated with cell death induced by Aß neurotoxicity, and its expression level could be up- and down-regulated by suppression or over expression of miR-124 level respectively. These findings suggest that miR-124 may work as a basilic regulating factor to alleviate cell death in the process of AD by targeting BACE1, play an essential role in the control of BACE1 gene expression, and might be considered as a novel therapeutic target in treating AD.

Protective effects of ω-conotoxin on amyloid-ß-induced damage in PC12 cells.

The present study was designed to investigate the potential neuroprotective effect of ω-conotoxin (ω-CTX) in a cell-based model of Alzheimer's disease (AD) using cultured PC12 cells incubated with ß-amyloid (Aß). Immunohistochemical staining, Western blot, MTT and TdT-mediated dUTP-biotin nick end labeling (TUNEL) analysis were employed to assess the cell viability and cell death. Aß in this model was clearly neurotoxic, inducing necrosis and apoptosis. ω-CTX antagonized the effects of Aß: there was an increase in cell viability and a suppression of inflammatory- and oxidative stress-related factors. These data suggest that ω-CTX may have neuroprotective actions against Aß-induced neurotoxicity. The significance of these new findings relative to the etiology and treatment of AD is discussed.

The neuroprotective effects of Reg-2 following spinal cord transection injury.

This study was designed to elucidate the potential neuroprotective effects of Reg-2 (regeneration gene protein 2) in a rodent model of spinal cord transection injury at the ninth thoracic level. Reg-2 at 100 and 500 µg, recombinant rat ciliary neurotrophic factor, or vehicle were delivered intrathecally using Alzet miniosmotic pumps. We found that Reg-2 treatment significantly reduced neuronal death in the spinal cord. There was also an attenuation of inflammation at the injury site and an increase in white matter sparing and retained myelination. Retrograde tracing revealed that Reg-2 protected axons of long descending pathways at 6 weeks post-SCI, and the number of FluoroGold-labeled neurons in spinal and supraspinal regions was also significantly increased. Immunofluorescent staining confirmed that the spared white matter contained neurofilament-positive axons. Moreover, behavioral improvements were revealed by Basso Beattie Bresnahan locomotor rating scores and grid-walk analysis. These results suggest that Reg-2 might promote functional recovery by increasing axonal growth, inhibiting neuronal apoptosis, and attenuating spinal cord secondary injury after SCI.

Activation of PAR2 or/and TLR4 promotes SW620 cell proliferation and migration via phosphorylation of ERK1/2.

Protease-activated receptor 2 (PAR2) is a G-protein-coupled receptor and its activation has been associated with the pathogenetic progress in certain cancers. Toll-like receptor 4 (TLR4), one member of Toll-like receptors family, is mainly contributed to the innate immune response. However, recent studies have shown that TLR4 is aberrantly expressed in various types of carcinomas and may correlate with tumor progression. Previously, we reported that PAR2 could be expressed in human colon cancer cell line (SW620) and its activation by some stimulants was able to facilitate cell proliferation and migration. In our recent preliminary experiment, it was found that SW620 cells also had TLR4 expression. Thus, we considered that PAR2 and TLR4 could have some collaborative roles in SW620 cells. In the current study, the cross-inducible expression of PAR2 and TLR4 on SW620 cells was investigated, and the functional roles of their activation on the behavior of SW620 cells were evaluated. It was found that activation of PAR2 with PAR2-AP (PAR2 agonist, 100 µM) enhanced TLR4 releasement and vice versa. The activation of PAR2 or TLR4 (with LPS, 100 ng/ml) could promote SW620 cell proliferation and migration, and the phosphorylation of ERK1/2 but not p38MAPK, as well as the expression of interleukin 8 (IL-8) and tissue factor (TF). Whereas the caspase-7 expression was decreased under PAR2 or TLR4 activation. Furthermore, ERK1/2 inhibitor (U0126, at 10 µM) could intervene in all regulating effects of PAR2 or/and TLR4. Collectively, this study demonstrated that both PAR2 and TLR4 activation on SW620 cells can trigger the phosphorylation of ERK1/2, regulate the expression of IL-8, TF and caspase-7, thereby promote the proliferation and migration of cells.

Decreased purinergic inhibition of synaptic activity in a mouse model of Niemann-Pick disease type C.

Niemann-Pick disease type C (NPC) is a progressive neurodegenerative disorder characterized by accumulation of free cholesterol in lysosomes, mainly due to a mutation in the NPC1 gene. The pathophysiological basis of the neural disorders in NPC, however, is not well understood. We found that the hippocampal field excitatory postsynaptic potential (fEPSP) was enhanced in NPC1 mutant mice. A1-receptor antagonist or adenosine degrading enzyme enhanced the fEPSP in both types of mice, but had a much weaker effect in the mutant mice, suggesting less tonic inhibition of synaptic transmission by endogenous adenosine in the mutant. Further evidence showed impaired hippocampal long term potentiation (LTP) in mutant mice. Supplement of A1 agonist N6-Cyclopentyladenosine (CPA) partially rescued the impaired LTP in mutant mice. Moreover, adenosine release from hippocampal slices was significantly decreased in the mutant. The enhanced excitatory synaptic transmission and the decreased synaptic plasticity due to the decreased adenosine release in NPC brain may partially contribute to the neural disorders of NPC disease, such as seizures, neurodegeneration, and dementia.

[Formaldehyde inhalation may damage olfactory bulb and hippocampus in rats].

OBJECTIVE: To investigate the effects of formaldehyde inhalation on the morphological damage, and Glu, GABA and NOS contents in olfactory bulb and hippocampus of rats. METHODS: Twenty SD rats were equally divided into two groups: rats in the control group inhaled fresh air, while the animals in experimental group were exposed to the air containing formaldehyde (12.5 mg/m(3), 4 h/d) for 7 days. Then rats were sacrificed and frozen sections of olfactory bulb and hippocampus were prepared. The morphological changes were examined and the Glu, GABA and NOS contents were detected using Nissl-staining, immunohistochemistry and Western blot, respectively. RESULT: Compared with the control group, there was a significant confusion and shrink of neuron morphology in experimental group, the number and staining intensity of Glu and NOS positive cells and protein contents were reduced. The protein expression of GABA was also decreased in the formaldehyde group. CONCLUSION: Formaldehyde inhalation can cause a severe morphological damage of olfactory bulb and hippocampus in SD rats,which may further impair memory and learning ability through the reduction of Glu, GABA and NOS expression.

Effects of Reg-2 on survival of spinal cord neurons in vitro.

Regeneration gene protein 2 (Reg-2) is a small secreted protein expressed in motor and sensory neurons of spinal cord during developmental stages and following injury of peripheral nerves. Reg-2 appears to act as a neurotrophic factor and protects injured neurons from death during regeneration. To illustrate these potential protective effects in vitro, we investigated the blocking effects of Reg-2 antibodies on the survival of primary cultured spinal cord neurons and astrocytes, as well as on neurite outgrowth. In addition, the effects of Reg-2 in neuron injury models induced by peroxide and mitochondrial poisoning were assessed. Our results showed that Reg-2 antibody markedly reduced survival and neurite outgrowth from neurons, whereas astrocyte survival was unaffected. Addition of Reg-2 into the culture medium had no effect on neuron survival or neurite outgrowth. However, the addition of the Reg-2 into culture media after peroxide treatment or cellular hypoxia insult induced by mitochondrial poisoning can reduce lactate dehydrogenase release levels and cell death. Thus, the data suggests that Reg-2 is essential for the survival and neurite outgrowth of developing spinal cord neurons but not the survival of glial cells, and that Reg-2 plays protective effects on spinal cord neurons against injury in vitro.

[Cortical neuron apoptosis induced by beta-amyloid peptide and protective effect of panoxadiol in mice].

OBJECTIVE: To investigate the apoptosis of cortical neurons induced by beta-amyloid peptide (Abeta(1-40)) and the protective effect of panoxadiol. METHODS: The Abeta(1-40) induced damage of primarily cultured mouse cortical neurons was examined with morphological observation, MTT assay, DNA agarose gel electrophoresis and Western-blot. RESULT: After 48 h treated with 12 mumol/L Abeta(1-40), the cortical neurons showed apoptotic characteristics: including decreased OD570 value in MTT assay, DNA cleavage fragment in electrophoresis and increased apoptotic cells. Western-blot showed that the expression of bcl-2 reduced significantly (P<0.05). Cell apoptosis was significantly attenuated in 40 mg/L panoxadiol treated group. CONCLUSION: Panoxadiol can protect cultured cortical neurons from apoptosis induced by Abeta(1-40) in mice.

The expression and the functional roles of tissue factor and protease-activated receptor-2 on SW620 cells.

Tissue factor (TF) is believed to play an important role in tissue repair, inflammation, angiogenesis, and tumor metastasis. Protease-activated receptors (PARs) are widely expressed on various cells including tumor cells and associated with many pathological mechanisms. In the present study, the expression of TF and PAR1, PAR2 on human colon cancer cells (SW620 and SW480) was investigated and their functional roles on the behavior of tumor cells were evaluated. It was demonstrated that SW620 and SW480 cells expressed TF at antigen, activity and mRNA levels. However, the highly metastatic cell line SW620 showed slightly higher TF expression than the low metastatic cell line SW480. The PAR2 antigen was strongly expressed on the membrane of SW620 cells, but not on SW480 cells. The PAR1 antigen was not observed in SW620 or SW480 cells, while PAR1 and PAR2 mRNA was detected in SW620 and SW480 cells. The migratory potential of SW620 was stronger than that of SW480 seen in Boyden chambers. PAR2 agonist (SLIGKV-NH2) and factor VIIa significantly stimulated SW620 cell proliferation, migratory activity, and interleukin 8 (IL-8) secretion compared to control. The stimulating effects of factor VIIa could be inhibited by anti-TF and anti-PAR2 but not anti-PAR1 antibodies. In summary, this study demonstrates that TF and PAR2 are strongly expressed on highly metastatic colonic tumor cells and are closely associated with the proliferation and migration of the cells. TF may elucidate its roles in colonic cancer invasion and metastasis via PAR2 pathway.