Molecular Cloning and Functional Analysis of Autophagy-related Gene Atg5 in Planarian Dugesia japonica / 中国生物化学与分子生物学报

Autophagy-related gene 5 (Atg5) plays an essential role in autophagy, the loss of its function impairs neurogenesis and axon regeneration. However, the biological function of Atg5 has not been characterized in planarian. Planarian is an ideal model for the study of brain regeneration. It can regenerate a new brain de novo in 1 week following amputation. To explore the role of Atg5 in planarian brain regeneration, we dissected the molecular characteristics of Atg5 in planarian Dugesia japonica (DjAtg5) and examined its function by RNAi. The full-length cDNA of DjAtg5 is 1 014 bp encoding 284 amino acids. The deduced amino sequence of DjAtg5 contains the functional Pfam domain of ATG5 and highly conserved residues for ATG5-ATG12 interaction. After amputation, the transcrips of DjAtg5 are increased and mainly distributed in the newly regenerated brain on day 3-5 of regeneration. However, knockdown of DjAtg5 by RNAi does not impair the regeneration ability and brain structure reformation, nor affects the neoblasts proliferation. Our results suggest that DjAtg5 participates in re-formation of planarian brain structure following amputation, but it is not an important regulator for planarian regeneration. However, autophagy inhibitor 3-MA can block planarian regeneration, which suggests that autophagy is necessary for planarian regeneration.

Expression profile of circularRNA during rat liver regeneration and its regulatory effect on cell proliferation / 解剖学报

Objective This study aims to investigate the expression profile and regulatory effect on cell proliferation of circular RNA(circRNA) in rat liver regeneration (LR). Methods CircRNA expression profile during rat LR of 114 rats ' regenerating liver which induced by 2/3 partial hepatectomy was detected by high-throughput sequencing. MiRanda and TargetScan were performed to predict their target microRNA (miRNAs) and mRNAs. Gene Ontology (GO) and IP A were used to analyze the physiological activities and signaling pathways they involved. Cytoscape v3. 0. 2 was used to construct the interaction network. Finally, the candidate key circRNAs were selected by the expression pattern combining with the number and function of target miRNAs. Results 20 878 circRNAs were detected during rat LR, among which 560 of them were differentially expressed, and 126 of them could bind to 117 target miRNAs, which were in turn to regulate 6510 downstream target mRNAs. They were involved in cell proliferation, stress response, substance metabolism and transforming growth factor-β (TGF-β), protein kinase A (PKA), Wnt/beta-catenin signaling pathways. 6 differential expressed circRNAs, including circRNA_03651, circRNA_03653, circRNA_04500, circRNA_05865, circRNA_l 1274 and circRNA_ 13559 might play a pivotal role in cell proliferation involved in rat LR by regulating 12 miRNAs and 15 mRNAs. Resultsing they were regarded as the candidate key circRNAs of rat LR. Conclusion 560 circRNAs were differentially expressed in rat LR, among which circRNA_03651, circRNA_03653, circRNA_04500, circRNA_05865, circRNA_l 1274 and circRNA_13559 might play a crucial role on cell proliferation involved in rat LR via 12 miRNAs-15 mRNAs axis.

Diagnosis of spine and spinal cord deformity in children with MRI / 中华实用儿科临床杂志

Objective To discuss the magnetic resonance imaging(MRI) characteristics of spine and spinal cord deformity in children.Methods Thirty-three children with spine and spinal cord deformity underwent MRI examination from Jan.2010 to Dec.2012.The technique was to obtain spin echo(SE) sagittal T1WI and fast spin echo(FSE) T2WI as well as axial FSE T2WI.Coronal FSE T2WI was added when necessary.Results There were 17 cases with spine deformity,accounting for 51.5％ of all patients,12 cases with both spine and spinal cord deformity,accounting for 36.4％ of all patients,4 cases with sacral canal cyst,accounting for 12.1％ of all patients.There were 4 cases of scoliosis,22 cases of scoliosis accompanying vertebral or spinal cord deformity,2 cases of atlas assimilation and basilar impression,1 case of bifid spine of the sacrum.Conclusions There are a great variety of paediatric spine and spinal cord deformities,and they always coexist.MRI can supply accurate diagnosis and useful information for clinic.

Ischemic postconditioning protects cardiomyocytes against ischemia/reperfusion injury by inducing MIP2

Cardiomyocytes can resist ischemia/reperfusion (I/R) injury through ischemic postconditioning (IPoC) which is repetitive ischemia induced during the onset of reperfusion. Myocardial ischemic preconditioning up-regulated protein 2 (MIP2) is a member of the WD-40 family proteins, we previously showed that MIP2 was up-regulated during ischemic preconditioning (IPC). As IPC and IPoC engaged similar molecular mechanisms in cardioprotection, this study aimed to elucidate whether MIP2 was up-regulated during IPoC and contributed to IPoC-mediated protection against I/R injury. The experiment was conducted on two models, an in vivo open chest rat coronary artery occlusion model and an in vitro model with H9c2 myogenic cells. In both models, 3 groups were constituted and randomly designated as the sham, I/R and IPoC/hypoxia postconditioning (HPoC) groups. In the IPoC group, after 45 min of ischemia, hearts were allowed three cycles of reperfusion/ischemia phases (each of 30 s duration) followed by reperfusion. In the HPoC group, after 6 h of hypoxia, H9c2 cells were subjected to three cycles of 10 minute reoxygenation and 10 minute hypoxia followed by reoxygenation. IPoC significantly reduced the infarct size, plasma level of Lactate dehydrogenase and creatine kinase MB in rats. 12 h after the reperfusion, MIP2 mRNA levels in the IPoC group were 10 folds that of the sham group and 1.4 folds that of the I/R group. Increased expression of MIP2 mRNA and attenuation of apoptosis were similarly observed in the HPoC group in the in vitro model. These effects were blunted by transfection with MIP2 siRNA in the H9c2 cells. This study demonstrated that IPoC induced protection was associated with increased expression of MIP2. Both MIP2 overexpression and MIP2 suppression can influence the IPoC induced protection.

Screen of inflammatory genes regulated by heat shock factor 1 and corroboration with SOCS3 gene / 中南大学学报(医学版)

OBJECTIVE@#To screen the inflammatory mediators genes regulated by HSF1, and explore the mechanism of downstream genes regulated by HSF1.@*METHODS@#HSF-/- and HSF1+/+ mice were injected with 15 mg/kg LPS intraperitoneally (ip), respectively, and were treated as previous after HSR. The total RNA of lung tissues were extracted and filtrated by SuperArray gene Microarry. The promoter of candidate genes were analyzed by transcription element search software to search for heat shock element (HSE). Select the suppressor of cytokine signaling 3 (SOCS3) with HSE. Macrophage cells were stimulated with 400 ng/mL LPS, and were treated as previous after HSR, then the total RNA was extracted respectively. RT-PCR and northern blot assay were performed to detect the expression levels of SOCS3 mRNA.@*RESULTS@#Fifteen genes were repressed by HSF1, including 9 genes with complete HSE. Eleven genes were accelerated by HSF1 possibly, including 8 genes with complete HSE. The promoter of SOCS3 gene contained one complete HSE. LPS stimulation obviously increased the levels of SOCS3 mRNA in macrophages of RAW264.7 mice, which was inhibited by HSR and over-expression of HSF1.@*CONCLUSION@#HSR or HSF1 inhibits LPS induced expression of SOCS3 mRNA; HSF1 might inhibit LPS-induced expression of SOCS3 mRNA by binding to HSE in the promoter of SOCS3 gene.

Immortalization of embryonic fibroblasts in heat shock transcription factor 1 knockout mouse / 中南大学学报(医学版)

OBJECTIVE@#To establish immortalized embryonic fibroblast lines in heat shock transcription factor 1 (HSF1) HSF1-/- and HSF1+/+ mice and to provide experimental models to study the function of HSF1.@*METHODS@#A mammalian expression vector (pSV3neo) containing the SV40 large T antigen was used to transfect the HSF1-/- and HSF1+/+ mouse embryonic fibroblast using Lipofectamine 2000. Colonies were screened by G418 and expanded to immortalized cell lines. PCR was used to detect the integration of the large T antigen with genome in the mouse embryonic fibroblast. Expression of SV40 large T antigen gene in expanded cells was identified by RT-PCR. HSP70 expression was examined by Western blot in the embryonic fibroblast lines.@*RESULTS@#The stable growth and serial propagation were observed in the HSF1-/- and HSF1+/+ cell lines for six months. The mRNA of SV40 T antigen gene expressed in the two cell lines. HSP70 expression could not be induced in the heat-treated HSF1-/- mouse embryo fibroblasts.@*CONCLUSION@#The immortalized cells of HSF1+/+ and HSF1-/- mouse embryo fibroblasts are successfully established.

Characteristics and expression of Mip5, a novel gene associated with myocardial ischemia/reperfusion in rats / 中南大学学报(医学版)

OBJECTIVE@#To determine the characteristics of a novel gene Mip5 (GenBank accession number AY553870) and its expression under physiological and pathological conditions.@*METHODS@#The characteristics of Mip5 were analyzed by bioinformatic programs including BLAST, spidey, psort, ClustalW and so on. RT-PCR was performed to detect Mip5 expression.@*RESULTS@#Bioinformatic analysis showed that Mip5 gene lied in the 13th chromosome and contained 8 exons and 7 introns, its open reading frame contained 909 bp and its protein production was 302 amino acid residues including 6 kelth domains. Under normal conditions, MIP5 expressed abundantly in the heart, brain and kidney, but its expression could not be detected in the liver and muscle. Expression of Mip5 gene was increased significantly after ischemia-reperfusion compared with the sham groups, and reached its peak at 3 h and recovered at 12 h after the reperfusion. Conclusion Mip5 gene is a novel gene containing a putative open reading frame of 302 amino acids residues and may play an important role in rat cardiomyocytes suffering ischemia processing.