Combinatorial effects of miR-20a and miR-29b on neuronal apoptosis induced by spinal cord injury.

Neuronal apoptosis is one of the prominent features involved in spinal cord injury (SCI). MicroRNAs (miRNAs) are small non-coding RNAs that functions in a variety of cellular processes including apoptosis. MiRNAs have been implicated as effectors of SCI. However, role of miRNAs in SCI-associated neuronal apoptosis remains to be investigated. A number of bioinformatics approaches have suggested Mcl-1 and BH3-only family genes as potential downstream targets regulated by miR-20a and miR-29b, respectively. To determine whether miR-20a and miR-29b play a role in neuronal apoptosis of SCI by regulating those genes, we transfected Neuro-2A neuroblastoma cells with mimic and inhibitor for the two miRNAs. The miR-20a mimic decreased Mcl-1 expression and the miR-29b mimic reduced the expression of Bad, Bim, Noxa and Puma. The repressor role of miR-20a and miR-29b is confirmed by the transfection of Neuro-2A cells with their inhibitor. Moreover, miR-20a mimic or miR-29b inhibitor attenuated Neuro-2A cell viability and co-transfection of both further diminished the viability of these cells. The in vitro effects of miR-20a and miR-29b on neuronal apoptosis were corroborated by the in vivo studies. Injection of miR-20a mimic or miR-29b inhibitor into the lesion of the injured spinal cord rescued the neuronal death and co-injection of both completely abolished SCI-induced apoptosis. In conclusion, altered expression of miR-20a and miR-29b may cooperatively contribute to the neuronal cell death of SCI through down-regulating anti-apoptotic myeloid cell leukemia sequence-1 (Mcl-1) and up-regulating pro-apoptotic BH3-only proteins.

MicroRNAs dysregulation in epilepsy.

Epilepsy is a syndrome characterized by recurrent spontaneous seizures due to neuronal hyperactivity in the brain. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate post-transcriptional expression of protein-coding mRNAs, which may have key roles in the pathogenesis of neurological disorders. Evidence indicates that miRNAs are emerging as a critical new layer of gene expression regulation with implications for the cause and treatment of epilepsy. Accumulating studies in epilepsy suggest that numerous specific miRNAs are dysregulated. Recent studies have explored several target genes and pathways of miRNAs in order to find out therapeutic approaches to epilepsy. Here, we review current findings regarding miRNA research in humans and animal models to provide a solid foundation for further research aiming at understanding the potential contribution of miRNAs to epilepsy pathophysiology.

SIRT2 polymorphism rs10410544 is associated with Alzheimer's disease in a Han Chinese population.

Sirtuin 2 (SIRT2) is a strong protein deacetylase, which is highly expressed in central nervous system. Recently, an association between SIRT2 rs10410544 polymorphism and late-onset Alzheimer's disease (LOAD) was found in the APOEε4-negative Caucasian population. To investigate the potential association between the rs10410544 C/T polymorphism of SIRT2 and the risk of LOAD, we conducted an independent replication case-control study in a Northern Han Chinese population comprising 1133 cases and 1159 healthy controls being matched for age and gender. The results revealed that there were significant differences in genotype and allele frequencies between LOAD cases and controls (genotype P=0.008, allele P=0.009). When compared with the C allele, the T allele of rs10410544 demonstrated a 1.709-fold risk for developing LOAD. After stratification by apolipoprotein E (APOE) ε4-carrying status, only APOEε4 noncarriers (P=0.035, adjusted OR=1.656, 95% CI: 1.036-2.647) showed the relation between LOAD and SIRT2 rs10410544 T allele. This study provides the evidence that the rs10410544 C/T polymorphism of SIRT2 was associated with genetic susceptibility to LOAD in a Northern Han Chinese population.

[Association of vitamin D receptor gene polymorphisms with Parkinson disease].

OBJECTIVE: Vitamin D receptor (VDR) has been proposed as a candidate gene for susceptibility to Parkinson's disease (PD). This study was set to assess the association between VDR gene Apa I and Taq I polymorphisms and PD in a Chinese Han population. METHODS: Two hundred and eighty five sporadic PD patients and 285 healthy controls were genotyped for the Apa I and Taq I polymorphisms in VDR gene using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: No significant difference was detected in genotype or allele distribution of both Apa I and Taq I polymorphisms between PD patients and controls (P U+003E 0.05). No TT genotype for Taq I was found in the studied population. For Taq I, the distribution of genotype was significantly different between male PD patients and controls (U+03C7 2=4.187, P=0.032, OR=2.149, 95%CI: 1.011-4.567), and the frequency of T allele was significantly higher in male PD patients than male controls (U+03C7 2=3.867, P=0.036, OR=2.064, 95%CI: 0.989-4.307). CONCLUSION: VDR gene Apa I polymorphisms are not associated with sporadic Parkinson's disease, but Taq I may be a risk factor for male PD.

Neuroprotective potential beyond immunoregulation of helminth infection as a therapeutic target in multiple sclerosis.

Multiple sclerosis (MS) is a common disabling autoimmune disease in young adults which does not have an effective treatment. The prevalence of immune-mediated diseases is higher in developed countries with hygienic environments, suggesting that helminthic infection may protect from autoimmune diseases. Previously, we reported that soluble egg antigens (SEA) from Schistosoma japonicum suppressed experimental autoimmune encephalomyelitis (EAE), an animal model of MS, through up-regulating T helper-2 (Th2) immune responses in both the peripheral and central target organs. Neurotrophins (NTs) are not exclusive to the nervous system. While immune cells, especially Th2 cells, can produce and secrete a variety of NTs resulting in neuroprotective immunity. NTs can also modulate immune responses by augmenting Th2 responses and downregulating Th1 responses. Interestingly, nerve growth factor (NGF) has been found in liver granulomas of Schistosoma mansoni-infected mice. Moreover, in the central nervous system of chronic schistosomiasis, NGF is increased. A hypothesis is hereby proposed - SEA derived from S. japonicum bears neuroprotective properties beyond its immunomodulatory effects. SEA can induce the expression of NTs, which in turn augment Th2 immune responses induced by SEA; whereby a positive regulatory circuit between Th2 responses and NTs comes into being.

[Bone marrow stromal cells transfected with ciliary neurotrophic factor gene ameliorates the symptoms and inflammation in C57BL/6 mice with experimental allergic encephalomyelitis].

OBJECTIVE: To investigate the anti-inflammatory effect of bone marrow stromal cells (MSCs) transfected with recombinant adenovirus-mediated ciliary neurotrophic factor (CNTF) gene in C57BL/6 mice with experimental allergic encephalomyelitis (EAE). METHODS: An adenovirus vector containing CNTF gene Ad-CNTF-IRES-GFP was constructed and transfected in the MSCs (MSC-CNTF). After examination of CNTF expression, the transfected cells were transplanted in C57BL/6 mice with MOG 35-55-induced EAE, which were monitored for the changes in the symptoms scores. The levels of tumor necrosis factor-alpha (TNF-alpha), inteferon-gamma (IFN-gamma), interleukin-12P35 (IL-12P35), and IL-10 in the peripheral blood of the mice were detected, and the number of MSC-CNTF cells in the spleen and spinal cord was counted. CD3+ T cell infiltration and TNF-alpha and IFN-gamma expressions in the lesions were also observed after the cell transplantation. RESULTS: CNTF gene transfection resulted in significantly increased CNTF expression in the MSCs. The mice receiving MSC-CNTF transplantation exhibited significantly improved symptoms with shortened disease course and lessened disease severity. The cell transplantation also resulted in significantly decreased peripheral blood TNF-alpha levels, ameliorated CD3+T cell infiltrations and lowered TNF-alpha expression in the lesions, while the levels of IFN-gamma underwent no significant changes. CONCLUSION: Transplantation of CNTF gene-transfected MSCs results in decreased peripheral blood TNF-alpha and IFN-gamma levels and reduced inflammatory cells, CD3-positive cells and TNF-alpha expression in the lesion of EAE, therefore providing better effect than MSCs in relieving the symptoms of EAE in mice.

[Emission spectrum of liquid CO-N2 mixture at shock compression].

Driving a copper projectile to impact a cryo-target made of aluminous alloy at the speed of 2.21 km x s(-1) with a two stage light gas gun, a proper one dimensional shockwave with a speed of 18.76 km x s(-1) was generated and directly acted on a uniform liquid in target, which was condensed by proportional gaseous carbon monoxide and nitrogen. At the measurement of Hugoniots, the full linear spectrum entirely dissociated with the plasma under the shock pressure of 33.5 GPa was caught by the use of intensified charge coupled device and accurate spectrographic technology. From the analysis of the spectrum, the authors know that the transient spectrograph with six channels can be used to measure and record the course of shock compression-irradiancy reliably, and the emitted spectral lines of shock compressed products indicated that the thermal dissociation and phase transition had occurred in homogeneous liquid of CO-N2. Furthermore, comparing the spectral intensity of lower central wavelength with that of higher, the fact of stronger intensity of 488 nm also validates that changes from "optic thin" to "optic thick" exist indeed in dense hydrocarbon liquid acted on by shock pressure.

Translocation and neuroprotective properties of transactivator-of-transcription protein-transduction domain-neuroglobin fusion protein in primary cultured cortical neurons.

Ngb (neuroglobin) is a newly discovered hexaco-ordinate globin that is expressed in vertebrate brain and peripheral nervous systems. Expression of Ngb increases in response to oxygen deprivation and protects neurons from hypoxia in vitro and in vivo. However, the lack of its transduction ability into cells resulted in limited neuroprotection. To educe its neuroprotection under hypoxia, a cell-permeable Ngb fusion protein was generated. A rat brain Ngb gene was cloned and fused with a gene fragment encoding the nine-amino-acid TAT PTD (transactivator-of-transcription protein-transduction domain; RKKRRQRRR) of HIV-1 in a prokaryotic expression vector to generate a genetic in-frame N-terminal hexahistidine-tagged) TAT PTD-Ngb fusion protein. It was expressed in soluble form in Escherichia coli BL21(DE3)plysS and purified with Ni(2+)-affinity chromatography. The results showed that the purified fusion protein TAT PTD-Ngb can enter into the primary cultured cortical neurons in a dose-dependent manner when added exogenously to the culture media and can be detected in cells within 48 h. The cell viability under hypoxia was increased and apoptosis induced by hypoxia was decreased after TAT PTD-Ngb was transduced into cortical neurons. The results provide a clue for the research of Ngb and suggest that transduction of TAT PTD-Ngb may be one of the ways for the therapy of CNS (central nervous system) diseases, especially cerebrovascular diseases and neurodegenerative diseases.