Expression of long non-coding RNAs in complete transection spinal cord injury: a transcriptomic analysis

Long non-coding RNAs(lncRNAs)are abundantly expressed in the central nervous system and exert a critical role in gene regulation via multiple biological processes.To uncover the functional significance and molecular mechanisms of lncRNAs in spinal cord injury(SCI),the expression signatures of lncRNAs were profiled using RNA sequencing(RNA-seq)technology in a Sprague-Dawley rat model of the 10th thoracic vertebra complete transection SCI.Results showed that 116 of 14,802 detected lncRNAs were differentially expressed,among which 16—including eight up-regulated(H19,Vof16,Hmox2-ps1,LOC100910973,Ybx1-ps3,Nnat,Gcgr,LOC680254)and eight down-regulated(Rmrp,Terc,Ngrn,Ppp2r2b,Cox6a2,Rpl37a-ps1,LOC360231,Rpph1)—demonstrated fold changes>2 in response to transection SCI.A subset of these RNA-seq results was validated by quantitative real-time PCR.The levels of 821 mRNAs were also significantly altered post-SCI;592 mRNAs were up-regulated and 229 mRNAs were down-regulated by more than 2-fold.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analyses showed that differentially expressed mRNAs were related to GO biological processes and molecular functions such as injury and inflammation response,wound repair,and apoptosis,and were significantly enriched in 15 KEGG pathways,including cell phagocytosis,tumor necrosis factor alpha pathway,and leukocyte migration.Our results reveal the expression profiles of lncRNAs and mRNAs in the rat spinal cord of a complete transection model,and these differentially expressed lncRNAs and mRNAs represent potential novel targets for SCI treatment.We suggest that lncRNAs may play an important role in the early immuno-inflammatory response after spinal cord injury.This study was approved by the Administration Committee of Experimental Animals,Guangdong Province,China.

Overexpression of Dickkopf-3 induces apoptosis through mitochondrial pathway in human colon cancer

AIM:To investigate the mechanisms of the biological roles of Dickkopf-3(Dkk-3) in cell invasion,survival and apoptosis in colon cancer cells.METHODS:Three human colon cancer cell lines,i.e.,HT-29,LoVo and SW480,were used.Overexpression of Dkk-3 induced by pEGFP-N1-Dkk-3-GFP plasmid in LoVo cells was performed using Lipofectamine 2000 reagent.Reverse transcription polymerase chain reaction and Western blotting were performed to determine the mRNA and protein expression levels of Dkk-3,respectively.Cell proliferation assay,cell cycle analysis,hoechst 33258 assay and Matrigel invasion assay were performed on Dkk-3 overexpressing transfectants.RESULTS:The mRNA and protein expressions of Dkk-3 in HT-29(mRNA:0.06 ± 0.02,protein:0.06 ± 0.01) and LoVo(mRNA:0.07 ± 0.02,protein:0.07 ± 0.02) cells were significantly lower than that in SW480 cells(mRNA:0.92 ± 0.04,protein:0.69 ± 0.13;all P < 0.05),and the greatest levels of invasiveness wasin LoVo cells.Dkk-3 overexpression inhibited the proliferation and invasion of LoVo cells and induced cell cycle arrest at G0/G1 phase and subsequent apoptosis,as indicated by increased chromatin condensation and fragments,upregulated Bax and cytochrome c protein,downregulated survivin and Bcl-2 protein,and the activation of caspase-3 and caspase-9.Furthermore,Dkk-3 overexpression reduced the accumulation of cytosolic fraction of β-catenin.CONCLUSION:Dkk-3 overexpression induced apoptosis in human colon cancer possibly through the mitochondrial pathway.Dkk-3 may be involved in the Wnt/β-catenin signaling pathways in colon cancer.

Regulation of innate immune responses by rabies virus

Rabies virus(RABV)is an infectious and neurotropic pathogen that causes rabies and infects humans and almost all warm-blooded animals,posing a great threat to people and public safety.It is well known that innate immunity is the critical first line of host defense against viral infection.It monitors the invading pathogens by recognizing the pathogen-associated molecular patterns and danger-associated molecular patterns through pattern-recognition receptors,leading to the production of type I interferons(IFNα/β),inflammatory cytokines,and chemokines,or the activation of autophagy or apoptosis to inhibit virus replication.In the case of RABV,the innate immune response is usually triggered when the skin or muscle is bitten or scratched.However,RABV has evolved many ways to escape or even hijack innate immune response to complete its own replication and eventually invades the central nervous system(CNS).Once RABV reaches the CNS,it cannot be wiped out by the immune system or any drugs.Therefore,a better understanding of the interplay between RABV and innate immu-nity is necessary to develop effective strategies to combat its infection.Here,we review the innate immune responses induced by RABV and illustrate the antagonism mechanisms of RABV to provide new insights for the control of rabies.

LSM12 facilitates the progression of colorectal cancer by activating the WNT/CTNNB1 signaling pathway

Aberrant activation of the WNT signaling pathway is a joint event in colorectal cancer(CRC),but the molecular mechanism is still unclear.Recently,RNA-splicing factor LSM12(like-Sm protein 12)is highly expressed in CRC tissues.This study aimed to verify whether LSM12 is involved in regulating CRC progression via regulating the WNT signaling pathway.Here,we found that LSM12 is highly expressed in CRC patient-derived tissues and cells.LSM12 is involved in the proliferation,invasion,and apoptosis of CRC cells,similar to the function of WNT signaling in CRC.Furthermore,protein interaction simulation and biochemical experiments proved that LSM12 directly binds to CTNNB1(also known asβ-Catenin)and regulates its protein stability to affect the CTTNB1-LEF1-TCF1 transcriptional complex formation and the associated WNT downstream signaling pathway.LSM12 depletion in CRC cells decreased the in vivo tumor growth through repression of cancer cell growth and acceleration of cancer cell apoptosis.Taken together,we suggest that the high expression of LSM12 is a novel factor leading to aberrant WNT signaling activation,and that strategies targeting this molecular mechanism may contribute to developing a new therapeutic method for CRC.

Preparation, Release-control and Cell Apoptosis of C_6 Glioma Cells in PEG-PLGA-Rg3 Nanoparticles

With biodegradable material poly（ethylene glycol）-poly（lactide-co-glycolide） （PEG-PLGA） as substrate, the size distribution of Rg3-NPs was approved by the scanning electron microscopy. MTT assay was used to detect the effects of Rg3-NPs on the growth rate of C6 cells at various concentrations and flow cytometry（FCM） was applied to assay the cell cycle and cell apoptosis of C6 glioma cells. Western blot analysis was used to measure the protein level of PCNA. The results show that Rg3-NPs are slick and uniformity, the average diameter of the nanoparticles is about 75-90 nm, entrapment efficiency is （89.7±1.7）%. MTT assay shows the growth of C6 Glioma Cells can be significantly inhibited by Rg3-NPs in a dose-dependence manner. FCM and Western blot analysis show Rg3 can be released from the conjugated nanoparticles to function in the cell nuclei so as to lead to the changes in the growth cycle of the cells, which results in the arrest of G0-G1 cell cycle and induces the apoptosis of C6 cells. Therefore, Rg3-NPs may be used for the auxiliary therapy of brain glioma.

Vascular endothelial growth inhibitor affects the invasion, apoptosis and vascularisation in breast cancer cell line MDA-MB-231

Background Breast cancer is one of the most common malignant female diseases worldwide.It is a significant threat to every woman＇s health.Vascular endothelial growth inhibitor （VEGI） is known to be abundant in endothelial cells.According to previous literature,overexpression of VEGI has been shown to inhibit tumor neovascularisation and progression in cellular and animal models,but there has been limited research on the significance of VEGI in the breast cancer.Methods In our study,cell lines MDA-MB-231 were first constructed in which VEGI mediated by lentivirus over-expressed.The effects of VEGI over-expression on MDA-MB-231 cells were investigated both in vitro and in vivo.The expression of VEGI in the MDA-MB-231 cells after infection of lentivirus was analyzed using real-time PCR and Western blotting.The effect of the biological characteristics of MDA-MB-231 cells was assessed by growth,invasion,adhesion,and migration assay with subcutaneous tumor-bearing nude mice models.Then the growth curves of the subcutaneous tumors were studied.Expressions of VEGI,CD31 and CD34 in the tumors were analyzed by immunohistochemistry and apoptosis was detected by flow cytometry and immunohistochemistry.Results Infection of MDA-MB-231 cells within the lentivirus resulted in approximately a 1 000-fold increase in the expression of VEGI.As can be seen in the invasion,adhesion and migration assay,the over-expression of VEGI can inhibit the ability of MDA-MB-231 cells during migration,adhesion and invasion.The volume of the subcutaneous tumor in the over-expression group was distinctly and significantly less than that of the control groups.Immunohistochemistry analysis of the tumor biopsies cleady showed the expression of VEGI in the over-expression group increased while CD31 and CD34 decreased significantly.In vitro and in vivo,the early apoptosis rate and the apoptosis index were increased within the VEGI over-expression group as compared with the control group.Conclusions Taken together,recombinant lentivirus that were successfully constructed,demonstrated up-regulated VEGI gene expression in breast cancer cells.Lentivirus-mediated over-expression of VEGI weakened the ability of the breast cancer cell migration,adhesion and invasion.Over-expression of VEGI diminished the tumorigenic capacity of breast cancer cells in vivo.Up-regulation of VEGI gene expression however inhibited breast cancer MDA-MB-231 cell in the early apoptosis.

Specific regulator of eosinophil apoptosis： Siglec-8 new hope for bronchial asthma treatment

Objective It is known that Siglec-8 is selectively expressed on human eosinophils at a high level and mediates eosinophil apoptosis when crosslinked with its antibody. The aim of our review is to elucidate the molecular and biological characteristic of Siglec-8 and then discuss the function and possible mechanisms of Siglec-8 in eosinophils. Thereby, we will expand our understanding to the regulation of eosinophil apoptosis, and provide important clues to the treatment of asthma and other hyper-eosinophilic diseases. Data sources Most articles were identified by searching of PubMed online resources using the key term Siglecs. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected. Results Siglec-8 is selectively expressed on human eosinophil and can specifically induce eosinophil apoptosis. Conclusion The restricted expression of Siglec-8 on human eosinophil and the rapid progress in understanding its role as cell signaling and activation of death receptors have made it an attractive target for treatment of asthma and other hyper-eosinophilic diseases.

Cyclovirobuxinum D Alleviates Cardiac Hypertrophy in Hyperthyroid Rats by Preventing Apoptosis of Cardiac Cells and Inhibiting the p38 Mitogen-Activated Protein Kinase Signaling Pathway

Objective： To investigate the underlying mechanisms of cyclovirobuxinum D（Cvb-D） on alleviating cardiac hypertrophy in rats. Methods： Sprague-Dawley rats were randomly divided into 5 groups： control group; levothyroxine-induced cardiac hypertrophy group（model）; levothyroxine-induced cardiac hypertrophy ＋ Cvb-D group（Cvb-D）; levothyroxine-induced cardiac hypertrophy ＋ captopril group（captopril）; levothyroxine-induced cardiac hypertrophy ＋ SB203580 group（SB203580）, n=10 for each group. Rats were daily administered the respective drugs continuously for14 days by gastric gavage. A rat model of cardiac hypertrophy was established by intraperitoneal injection of levothyroxine to investigate whether Cvb-D protects against cardiac hypertrophy by inhibiting the p38 mitogen-activated protein kinase（MAPK） signaling pathway and preventing apoptosis of cardiac cells. Results： Treatment with Cvb-D significantly deceased left ventricle hypertrophy, improved the histopathology, hemodynamic conditions, and cardiac function in rats with cardiac hypertrophy. Compared with the normal control group, in rats with cardiac hypertrophy, expression of bax in the heart and phospho-p38 MAPK protein levels were significantly up-regulated（P〈0.01 or 0.05）, whereas the bcl-2 protein level was downregulated（P〈0.01）. In contrast, Cvb-D treatment reversed the changes in bax and phospho-p38 MAPK protein levels but increased the bcl-2 protein level（P〈0.01 or 0.05）, and these effects were similar to those of captopril and SB203580（a specific p38 MAPK inhibitor） treatment. Furthermore, both Cvb-D, captopril and SB203580 reduced m RNA expression of p38α, p38β, c-fos, and c-jun m RNA, and Cvb-D had a stronger effect（P〈0.01）. Conclusion： These results demonstrate that Cvb-D protects against cardiac hypertrophy, which is possibly mediated by prevention of cardiac cell apoptosis and inhibition of the p38 MAPK signaling pathway.