Dataset Information

Cycling exercise affects the expression of apoptosis-associated microRNAs after spinal cord injury in rats.

ABSTRACT: There are two major aspects to a spinal cord injury (SCI): an acute, primary mechanical trauma and a progressive phase of secondary tissue damage provoked by inflammation, excitotoxicity, apoptosis, and demyelination. MicroRNAs (miRs) are small, ~22 nucleotide, non-protein-coding RNAs that function at the post-transcriptional level to regulate gene expression. They have important roles in homeostatic processes such as cell proliferation and programmed cell death. In the injured rat spinal cord we performed an expression analysis of miRs and their downstream targets involved in apoptotic pathways and used post-injury cycling exercise to test for activity-dependent plasticity of miR expression. We show that SCI results in increased expression of miR Let-7a and miR16 while exercise leads to elevated levels of miR21 and decreased levels of miR15b. These changes in miR expression are correlated with changes in expression of their target genes: pro-apoptotic (decreased PTEN, PDCD4, and RAS mRNA) and anti-apoptotic (increased Bcl-2 mRNA) target genes. This is accompanied by a down-regulation of mRNA for caspase-7 and caspase-9 and reduced levels of caspase-7 protein. These results indicate possible beneficial effects of exercise through action on multiple miRs and their targets that contribute to the functional regulation of apoptosis after SCI.

SUBMITTER: Liu G

PROVIDER: S-EPMC2963016 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Cycling exercise affects the expression of apoptosis-associated microRNAs after spinal cord injury in rats.

Liu Gang G Keeler Benjamin E BE Zhukareva Victoria V Houlé John D JD

Experimental neurology 20100916 1

There are two major aspects to a spinal cord injury (SCI): an acute, primary mechanical trauma and a progressive phase of secondary tissue damage provoked by inflammation, excitotoxicity, apoptosis, and demyelination. MicroRNAs (miRs) are small, ~22 nucleotide, non-protein-coding RNAs that function at the post-transcriptional level to regulate gene expression. They have important roles in homeostatic processes such as cell proliferation and programmed cell death. In the injured rat spinal cord w ...[more]

PMID: 20816819

Similar Datasets

Project description:BackgroundThere is emerging evidence that astaxanthin plays a significant role in protecting neuro-cells from apoptosis after central nervous system injury. Our study examined the effects of astaxanthin on neuro-cell apoptosis after spinal cord injury.MethodsOne hundred and forty-four healthy adult Sprague-Dawley rats were randomly divided into the experimental group, control group, and sham operation group (n=48). Spinal cord injury was induced using the modified Allen method in the control group and the experimental group; while in the sham operation group, the lamina was removed without spinal cord injury. The rats in the experimental group were given astaxanthin (75 mg/kg) by gavage immediately after the operation, and in the other groups were given the same amount of olive oil. Motor function was assessed by blood-brain barrier (BBB) scores. The malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD) at 24 h was determined after the operation. The apoptosis index (AI) was determined at 6, 24, and 48 h after the operation. At 48 h after the operation, we calculated the water content of the spinal cord, the lesion ratio of the spinal cord, the ultrastructure of the spinal cord, and the ultrastructure score.ResultsThe BBB scores of the control and experimental groups were significantly lower than the sham operation group at each postoperative time (P<0.05), and the BBB score of the experimental group was significantly higher than the control group at 1-4 weeks postoperatively (P<0.05). At 24 hours postoperatively, MDA content was highest in the control group and lowest in the sham operation group, while SOD activity was highest in the sham operation group and lowest in the control group (P<0.05). At each time point postoperatively, the sham operation group had the lowest AI and the control group had the highest AI (P<0.05). At 48 h after the operation, the water content and the lesion ratio of the spinal cord, and the ultrastructure score were the lowest in the sham operation group and the highest in the control group (P<0.05).ConclusionsAstaxanthin significantly improved the motor function of rats with spinal cord injury.

Project description:BackgroundSpinal cord ischemia/reperfusion injury (SCII) is one of the most serious spinal cord complications that stem from varied spine injuries or thoracoabdominal aortic surgery. Nevertheless, the molecular mechanisms underlying the SCII remain unclear.MethodsMale Sprague-Dawley (SD) rats were randomly divided into 5 groups of sham, SCII 24 h, SCII 72 h, sevoflurane preconditioning SCII 24 h (SCII 24 h+sevo), and sevoflurane preconditioning SCII 72 h (SCII 72 h+sevo) group. We then analyzed the expression of differentially expressed micro RNAs (DEmiRNAs) in these groups and their target genes. Functional enrichment analysis of their target genes was further performed using Metascape software. The microRNA-messenger RNA-pathway (miRNA-mRNA-pathway) network and the sevoflurane-miRNA-mRNA-pathway integrative network were further constructed to explore the molecular mechanisms underlying SCII and neuroprotective effects of sevoflurane against SCII. Molecular docking was also performed to evaluate the interactions between hub targets and sevoflurane. Finally, the expression levels of miR-21-5p and its target genes [mitogen-activated protein kinase kinase 3 and protein phosphatase 1 regulatory subunit 3B (MAP2K3 and PPP1R3B)] were measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analyses.ResultsWe found that sevoflurane alters several miRNA expression following SCII at 24 and 72 h after reperfusion. It was shown that miR-221-3p, miR-181a-1-3p, and miR-21-5p were upregulated both at 24 and 72 h in the sevoflurane pre-treatment reperfusion groups. Functional enrichment analysis revealed that target genes for the above co-DEmiRNAs at 24 and 72 h in the SCII group with sevoflurane pretreatment participated in the mitogen-activated protein kinase (MAPK), ErbB, apoptosis, and transforming growth factor-beta (TGF-beta) signaling pathways. Both MAP2K3 and PPP1R3B were found to be common targets for sevoflurane and miRNA-mRNA-pathway (rno-miR-21-5p). It was shown that MAP2K3 regulates the MAPK signaling and the T cell receptor signaling pathways, whereas PPP1R3B regulates the ErbB signaling pathway. Molecular docking further revealed that sevoflurane strongly binds the MAP2K3 and PPP1R3B proteins. Compared to the sham group, SCII induced significant under-expression of miR-21-5p but upregulated PPP1R3B and MAP2K3 proteins; sevoflurane pretreatment increased the expression of miR-21-5p but decreased those of PPP1R3B and MAP2K3 proteins.ConclusionsIn general, sevoflurane regulates the expression of several miRNAs following SCII. In particular, sevoflurane might protect against SCII via regulating the expression of miR-21-5p, its target genes (MAP2K3 and PPP1R3B), and related signaling pathways.

Project description:Spinal cord ischemia-reperfusion injury (SCII) is a pathological process with severe complications such as paraplegia and paralysis. Aberrant miRNA expression is involved in the development of SCII. Differences in the experimenters, filtering conditions, control selection, and sequencing platform may lead to different miRNA expression results. This study systematically analyzes the available SCII miRNA expression data to explore the key differently expressed miRNAs (DEmiRNAs) and the underlying molecular mechanism in SCII. A systematic bioinformatics analysis was performed on 23 representative rat SCII miRNA datasets from PubMed. The target genes of key DEmiRNAs were predicted on miRDB. The DAVID and TFactS databases were utilized for functional enrichment and transcription factor binding analyses. In this study, 19 key DEmiRNAs involved in SCII were identified, 9 of which were upregulated (miR-144-3p, miR-3568, miR-204, miR-30c, miR-34c-3p, miR-155-3p, miR-200b, miR-463, and miR-760-5p) and 10 downregulated (miR-28-5p, miR-21-5p, miR-702-3p, miR-291a-3p, miR-199a-3p, miR-352, miR-743b-3p, miR-125b-2-3p, miR-129-1-3p, and miR-136). KEGG enrichment analysis on the target genes of the upregulated DEmiRNAs revealed that the involved pathways were mainly the cGMP-PKG and cAMP signaling pathways. KEGG enrichment analysis on the target genes of the downregulated DEmiRNAs revealed that the involved pathways were mainly the Chemokine and MAPK signaling pathways. GO enrichment analysis indicated that the target genes of the upregulated DEmiRNAs were markedly enriched in biological processes such as brain development and the positive regulation of transcription from RNA polymerase II promoter. Target genes of the downregulated DEmiRNAs were mainly enriched in biological processes such as intracellular signal transduction and negative regulation of cell proliferation. According to the transcription factor analysis, the four transcription factors, including SP1, GLI1, GLI2, and FOXO3, had important regulatory effects on the target genes of the key DEmiRNAs. Among the upregulated DEmiRNAs, miR-3568 was especially interesting. While SCII causes severe neurological deficits of lower extremities, the anti-miRNA oligonucleotides (AMOs) of miR-3568 improve neurological function. Cleaved caspase-3 and Bax was markedly upregulated in SCII comparing to the sham group, and miR-3568 AMO reduced the upregulation. Bcl-2 expression levels showed a opposite trend as cleaved caspase-3. The expression of GATA6, GATA4, and RBPJ decreased after SCII and miR-3568 AMO attenuated this upregulation. In conclusion, 19 significant DEmiRNAs in the pathogenesis of SCII were identified, and the underlying molecular mechanisms were validated. The DEmiRNAs could serve as potential intervention targets for SCII. Moreover, inhibition of miR-3568 preserved hind limb function after SCII by reducing apoptosis, possibly through regulating GATA6, GATA4, and RBPJ in SCII.

Dataset Information

Cycling exercise affects the expression of apoptosis-associated microRNAs after spinal cord injury in rats.

Publications

Cycling exercise affects the expression of apoptosis-associated microRNAs after spinal cord injury in rats.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets