Inhibition of genes expression of SARS coronavirus by synthetic small interfering RNAs

RNA interference (RNAi) is triggered by the presence of a double-stranded RNA (dsRNA), and results in the silencing of homologous gene expression through the specific degradation of an mRNA containing the same sequence. dsRNAmediated RNAi can be used in a wide variety of eucaryotes to induce the sequence-specific inhibition of gene expression.Synthetic 21-23 nucleotide (nt) small interfering RNA (siRNA) with 2 nt 3' overhangs was recently found to mediate efficient sequence-specific mRNA degradation in mammalian cells. Here, we studied the effects of synthetic siRNA duplexes targeted to SARS coronavirus structural proteins E, M, and N in a cell culture system. Among total 26 siRNA duplexes, we obtained 3 siRNA duplexes which could sequence-specifically reduce target genes expression over 80％ at the concentration of 60 nM in Vero E6 cells. The downregulation effect was in correlation with the concentrations of the siRNA duplexes in a range of 0～60 nM. Our results also showed that many inactive siRNA duplexes may be brought to life simply by unpairing the 5' end of the antisense strands. Results suggest that siRNA is capable of inhibiting SARS coronavirus genes expression and thus may be a new therapeutic strategy for treatment of SARS.

Combination of small interfering RNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cells

AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h, 72 h and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay （ELISA）. Intracellular viral DNA and covalently closed circular DNA （cccDNA） were quantified by real-time polymerase chain reaction （PCR）. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR （RT-PCR）. RESULTS： siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dosedependent manner. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication. More importantlycombination of siRNAs significantly suppressed HBV cccDNA amplification. CONCLUSION： Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells, especially on cccDNA amplification.

KNOCKDOWN OF SURVIVIN EXPRESSION BY SMALL INTERFERING RNA SUPPRESSES PROLIFERATION OF TWO HUMAN CANCER CELL LINES

Objective To construct an expression vector of small interfering RNA （siRNA） against survivin and observe its effects on survivin expression and proliferation of human pancreatic cancer cell line PC-2 and breast cancer cell line MCF-7. Methods Constructed an expression vector of siRNA against survivin and transfected it into PC-2 and MCF-7 cells using lipofectamine^TM 2000. The expression of survivin was detected by semi-quanfifive RT-PCR and immunohistochemistry, and its effects on proliferation of PC-2 and MCF-7 cells were detected by MTT assay. Results The introduction of sequence-specific siRNA could efficiently suppress survivin expression at both mRNA and protein levels in the two cancer cell lines. In PC-2 cells, the expression inhibition rates were 81.25% at mRNA level and 74.24% at protein level In MCF-7 cells, the expression inhibition rates were 64.91% at mRNA level and 79. 72% at protein level The proliferation of PC-2 and MCF-7 cells was also suppressed, and24 and 48 hours after the cells were reseeded, the proliferation inhibition rates of PC-2 cells were 28. 00% and 33. 38%, and that of MCF-7 cells were 31.58% and 33.02%, respectively. Conclusions The expression vector of siRNA against survivin can block survivin expression in PC-2 and MCF-7 cells efficiently and specifically. Down regulation of survivin expression can suppress proliferation of PC-2 and MCF-7 cells. Survivin RNAi may have potential value in gene therapy of human cancers.

Small interfering RNA targeting PGC-1α inhibits VEGF expression and tube formation in human retinal vascular endothelial cells

AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O2) or hypoxic (1%, O2) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O2) or hypoxic (1%, O2) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.

Progress of Targeting Transforming Growth Factor-β1 Small Interfering RNA in Liver Fibrosis

Liver fibrosis is a common pathological consequence of a variety of chronic stimuli, including viral, autoimmune, drug-induced, cholestatic and metabolic diseases. Fibrosis is driven by a dynamic process involving increased synthesis of matrix components and a failure of physiological mechanisms of matrix turnover. Activation of hepatic stellate cells(HSCs) remains a central event in fibrosis. HSCs are the main source of extracellular matrix(ECM). Transforming growth factor-beta(TGF-β), which is the fibrogenic master cytokine, can induce the activation of HSCs to produce a large amount of ECM, and is capable of inducing apoptosis of liver cells. RNA interference(RNAi) is a novel gene disruption technology. Studies have shown that small interfering RNA(si RNA) targeting TGF-β1 may inhibit the activation and proliferation of HSCs, suppress ECM synthesis and block liver fibrosis. TGF-β1 si RNA-mediated gene silencing therapy provides a new avenue for liver fibrosis. This review summarizes recent progresses in research on HSCs, TGF-β1 and TGF-β1 si RNA in liver fibrosis.

Impact of Bovine Skeletal Muscle Satellite Cell Differentiation by Small Interfering RNA Targeting Myogenin Gene

To examine the effect of myogenin gene on the differentiation of bovine skeletal muscle satellite cell, we constructed small interfering RNA plasmid vector to obtain myogenin knockdown bovine skeletal muscle cells, then used cell transfection, real time RCR and Western Blot to detect the influence of myogenin to cell differentiation. Results showed that the knockdown of myogenin significantly decreased its expression and other muscle-specific genes. Compared to the control, it could differentiate into few myotubes when challenged by low serum in the medium. These findings provided an important theoretical basis for further explore of the genetic mechanism in adult skeletal muscle, the remedy of muscle injuries and the cultivation of high-yield transgenic cattle.

Effects of Small Interfering RNATargeting Sphingosine Kinase-1 Gene on the Animal Model of Alzheimer's Disease

Summary： Alzheimer＇s disease （AD） is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. Abnormal sphingolipid metabolism was reported in AD previously. This study aimed to investigate whether sphK1 could exacerbate the accumulation of amyloid protein （Aβ） and sharpen the learning and memory ability of the animal model of AD using siRNA interference. An adenovirus vector expressing small interfering RNA （siRNA） against the sphK1 gene （sphKl-siRNA） was designed, and the effects of sphKl-siRNA on the APP/PS1 mouse four weeks after treatment with sphKl-siRNA hippocampal injection were examined. SphK1 protein expression was confirmed by using Western blotting and ceramide content coupled with SIP secretion was evaluated by enzyme-linked immunosorbent assay （ELISA）. Aβ load was detected by immunohistochemical staining and ELISA. Morris water maze was adopted to test the learning and memory ability of the APP/PS 1 mice. A significant difference in the expression of sphK1 protein and mRNA was observed between the siRNA group and the control group. Aβ load in transfected mice was accelerated in vivo, with significant aggravation of the learn- ing and memory ability. The sphKl gene modulation in the All load and the learning and memory ability in the animal model of AD may be important for the treatment of AD.

The influence of small interfering RNA on the expression of Survivin in human glioma cells

Objective This study aims to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which is influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA

Small Interfering RNA Targeting TNF-α Gene Significantly Attenuates Renal Ischemia-Reperfusion Injury in Mice

Tumor necrosis factor-alpha（TNF-α） has been found to be centrally involved in the development of ischemia-reperfusion injury（IRI）-induced inflammation and apoptosis. Knockdown of TNF-α gene using small interfering RNA（si RNA） may protect renal IRI. Renal IRI was induced in mice by clamping the left renal pedicle for 25 or 35 min. TNF-α si RNA was administered intravenously to silence the expression of TNF-α. The therapeutic effects of si RNA were evaluated in terms of renal function, histological examination, and overall survival following lethal IRI. A single systemic injection of TNF-α si RNA resulted in significant knockdown of TNF-α expression in ischemia-reperfusion injured kidney. In comparison with control mice, levels of BUN and serum creatinine were significantly reduced in mice treated with si RNA. Pathological examination demonstrated that tissue damage caused by IRI was markedly reduced as a result of TNF-α si RNA treatment. Furthermore, survival experiments showed that nearly 90% of control mice died from lethal IRI, whereas more than 50% of si RNApretreated mice survived until the end of the eight-day observation period. We have demonstrated for the first time that silencing TNF-α by specific si RNA can significantly reduce renal IRI and protect mice against lethal kidney ischemia, highlighting the potential for si RNA-based clinical therapy.

Small interfering RNA for cancer treatment:overcoming hurdles in delivery

In many ways,cancer cells are different from healthy cells.A lot of tactical nano-based drug delivery systems are based on the difference between cancer and healthy cells.Currently,nanotechnology-based delivery systems are the most promising tool to deliver DNA-based products to cancer cells.This review aims to highlight the latest development in the lipids and polymeric nanocarrier for siRNA delivery to the cancer cells.It also provides the necessary information about siRNA development and its mechanism of action.Overall,this review gives us a clear picture of lipid and polymer-based drug delivery systems,which in the future could form the base to translate the basic siRNA biology into siRNA-based cancer therapies.

Small interfering RNA-mediated knockdown of Notch1 in lung T cells of asthmatic mice affects T cell differentiation

Background The immunologic response to allergens mediated by T lymphocytes is an incipient key element in the pathogenesis of asthma, and Thl/Th2 balance is regarded as the core of asthma pathogenesis. Notch is a single-pass transmembrane receptor protein that regulates differentiation, proliferation and apoptosis in a broad range of cells. It is considered that the Notch signal pathway works in every stage of T cell development and differentiation. Whether the pathway of asthma pathogenesis is related to Notch1 remains unknown. This study is aimed to investigate whether the pathway of asthma pathogenesis is related to Notch1 by examining the effect of knockdown of the Notch1 gene by small interfering RNA on T cell differentiation. Methods An OVA-induced asthma mouse model was established. The expression of Notch1 in the tissue and T cells of the lung from asthmatic mice was detected by RT-PCR and Western blotting. The expression of Notch1 and cytokine interleukin （IL）-4 and interferon （IFN）-γ in activated lung T cells was detected by RT-PCR and enzyme-linked immunosorbent assay after blocking Notch1 by small interfering RNA. Results The mRNA and protein expression of Notch1 increased significantly both in the lung tissue and lung T cells of asthmatic mice （both P 〈0.05）. IL-4 decreased and IFN-y increased significantly in active lung T cells after Notch1 was blocked by Notchl-specific small interfering RNA （IL-4： （2.51±0.51） pg/ml vs 0.64±0.27） pg/ml protein; IFN-γ： （21.72±4.24） pg/ml vs （39.79±4.09） pg/ml protein, P 〈0.05）. Conclusion This study demonstrated that the Notch1 signal might play a role in the pathogenesis of asthma by its involvement in Thl/Th2 differentiation.

Small interfering RNA targeting of keratin 17 reduces inflammation in imiquimod-induced psoriasis-like dermatitis

Background:Psoriasis is a common chronic inflammatory skin disease with 2%to 3%prevalence worldwide and a heavy social-psychological burden for patients and their families.As the exact pathogenesis of psoriasis is still unknown,the current treatment is far from satisfactory.Thus,there is an urgent need to find a more effective therapy for this disease.Keratin 17(K17),a type I intermediate filament,is overexpressed in the psoriatic epidermis and plays a critical pathogenic role by stimulating T cells in psoriasis.Therefore,we hypothesized that inhibiting K17 may be a potential therapeutic approach for psoriasis.This study aimed to investigate the therapeutic effect of K17-specific small interfering RNA(siRNA)on mice with imiquimod(IMQ)-induced psoriasis-like dermatitis.Methods:Eight-week-old female BALB/c mice were administered a 5%IMQ cream on both ears to produce psoriatic dermatitis.On day 3,K17 siRNA was mixed with an emulsion matrix and applied topically to the left ears of the mice after IMQ application every day for 7 days.The right ears of the mice were treated in parallel with negative control(NC)siRNA.Inflammation was evaluated by gross ear thickness,histopathology,the infiltration of inflammatory cells(CD3+T cells and neutrophils)using immunofluorescence,and the expression of cytokine production using real-time quantitative polymerase chain reaction.The obtained data were statistically evaluated by unpaired t-tests and a one-way analysis of variance.Results:The severity of IMQ-induced dermatitis on K17 siRNA-treated mice ears was significantly lower than that on NC siRNA-treated mice ears,as evidenced by the alleviated ear inflammation phenotype,including decreased ear thickness,infiltration of inflammatory cells(CD3+T cells and neutrophils),and inflammatory cytokine/chemokine expression levels(interleukin 17[IL-17],IL-22,IL-23,C-X-C motif chemokine ligand 1,and C-C motif chemokine ligand 20)(P<0.05 vs.the Blank or NC siRNA groups).Compared to the NC siRNA treatment,the K17 siRNA treatment resulted in increased K1 and K10 expression,which are characteristic of keratinocyte differentiation(vs.NC siRNA,K17 siRNA1 group:K1,t=4.782,P=0.0050;K10,t=3.365,P=0.0120;K17 siRNA2 group:K1,t=4.104,P=0.0093;K10,t=4.168,P=0.0042;siRNA Mix group:K1,t=3.065,P=0.0221;K10,t=10.83,P<0.0001),and decreased K16 expression,which is characteristic of keratinocyte proliferation(vs.NC siRNA,K17 siRNA1 group:t=4.156,P=0.0043;K17 siRNA2 group:t=2.834,P=0.0253;siRNA Mix group:t=2.734,P=0.0250).Conclusions:Inhibition of K17 expression by its specific siRNA significantly alleviated inflammation in mice with IMQ-induced psoriasis-like dermatitis.Thus,gene therapy targeting K17 may be a potential treatment approach for psoriasis.

Development of fluorinated polyplex nanoemulsions for improved small interfering RNA delivery and cancer therapy

We report the development of a small interfering RNA （siRNA） delivery vector based on cationic perfluorocarbon nanoemulsions. We have prepared perfluorodecalin （PFD） emulsions with a positive surface charge provided by a fluorinated poly（ethylenimine） （F-PEI）. The fluorinated emulsion （F-PEI@PFD） reduced cytotoxicity of F-PEI and demonstrated effective binding with siRNAs to form nanosized emulsion polyplexes. The prepared emulsion polyplexes enhanced cellular uptake and improved endosomal escape of the siRNA. In addition to increased reporter gene silencing in multiple cancer cell lines, when compared with control F-PEI and PEI polyplexes, the siR_NA emulsion polyplexes showed an excellent resistance to serum deactivation and maintained high activity, even in high-serum conditions. The F-PEI@PFD emulsion polyplexes carrying an siRNA to silence the expression of Bcl2 gene induced apoptosis and inhibited tumor growth in a melanoma mouse model in vivo and showed potential for in vivo ultrasound imaging. This study demonstrates the potential of F-PEI@PFD emulsions as a multifunctional theranostic nanoplatform for safe siRNA delivery, with integrated ultrasound imaging functionality.

Small interfering RNA-mediated inhibition of hepatitis G virus gene expression in human hepatoma cell Huh-7

The RNA interference(RNAi)phenomenon is a recently observed process in which the introduction of a double-stranded,small interfering RNA(siRNA)into a cell causes the specific degradation of a homologous single-stranded RNA.It represents an exciting new technology that could have therapeutic applications for the treatment of viral infections.Since hepatitis G virus(HGV)genome is a positive-sense single-stranded RNA,the replication of HGV does not lead to an integrated DNA genome,suggesting a particularly attractive target for RNAi study that could eliminate viral RNA from infected cells.The eukaryotic expression vector pVAX.EH containing the cDNA sequences of the entire HGV structural genes and hygromycin resistance gene downstream from the encephalomyocarditis virus(ECMV)internal ribosome entry site(IRES)was constructed and transfected into human hepatoma cell Huh-7.The modified cleavage products of the structural proteins of HGV expressed in hygromycin-resistant cell line Huh-7-EH were confirmed by RT-PCR and Western blot methods.Two specific HGV E2 siRNAs(1-E2siRNA,2-E2 siRNA)synthesized with T7 RNA polymerase by transcription in vitro were transfected into the Huh-7-EH cells.With the analyses of Western blot and the formation of hygromycin-resistant colonies,the inhibitions of expression of HGV structural protein by two HGV E2siRNAs were detected and found lasting at least one week.The inhibition of 2-E2 siRNA was stronger and only 1%of the cells treated with 2-E2 siRNA formed hygromycin-resistant colonies.These results support that specific HGV 2-E2 siRNAs mediate the degradation of mRNA spanning from HGV structural gene cDNA to hygromycin resistance gene in a majority of cells.In conclusion,the Huh-7-EH cells expressing HGV structural proteins stably can be used as a cell model for studying the replication of HGV and RNAi and the enlargement of RNAi may exist,in mammalian cells.

Remodeling the tumor immune microenvironment via siRNA therapy for precision cancer treatment

How to effectively transform the pro-oncogenic tumor microenvironments(TME)surrounding a tumor into an anti-tumoral never fails to attract people to study.Small interfering RNA(siRNA)is considered one of the most noteworthy research directions that can regulate gene expression following a process known as RNA interference(RNAi).The research about siRNA delivery targeting tumor cells and TME has been on the rise in recent years.Using siRNA drugs to silence critical proteins in TME was one of the most efficient solutions.However,the manufacture of a siRNA delivery system faces three major obstacles,i.e.,appropriate cargo protection,accurately targeted delivery,and site-specific cargo release.In the following review,we summarized the pharmacological actions of siRNA drugs in remolding TME.In addition,the delivery strategies of siRNA drugs and combination therapy with siRNA drugs to remodel TME are thoroughly discussed.In the meanwhile,the most recent advancements in the development of all clinically investigated and commercialized siRNA delivery technologies are also presented.Ultimately,we propose that nanoparticle drug delivery siRNA may be the future research focus of oncogene therapy.This summary offers a thorough analysis and roadmap for general readers working in the field.

Inhibition effect of small interfering RNA of connective tissue growth factor on the expression of vascular endothelial growth factor and connective tissue growth factor in cultured human peritoneal mesothelial cells

Background The peritoneum response to peritoneal dialysis can lead to fibrosis. The transforming growth factor β1 （TGF-β1 ） plays a key role in regulating tissue repair and remodelling after injury. Connective tissue growth factor （CTGF）, a downstream mediator of TGF-β1 inducing fibrosis, has been implicated in peritoneal fibrosis. Vascular endothelial growth factor （VEGF） plays a key role in angiogenesis that can hasten peritoneal fibrosis. In this study, we investigated the effect of small interfering RNA （siRNA） of CTGF by pRETRO-SUPER （PRS） retrovirus vector on the expression of CTGF and VEGF in human peritoneal mesothelial cells. Methods Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred into packaging cell line PT67 with lipofectamine, and the virus supernatant was used to infect human peritoneal mesothelial cell （HPMC）. The cells were divided into seven groups： low glucose DMEM, low glucose DMEM ＋ TGF-β1 5 ng/ml, low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS-CTGF-siRNA1-4 and low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS. The expression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot. Results Low levels of CTGF and VEGF were detected in confluent HPMCs. Following stimulation with TGF-β1 , the levels of CTGF and VEGF were significantly upregulated （P〈0.01）. Introduction of PRS-CTGF-siRNA1-4 resulted in the significant reduction of CTGF mRNA and protein, and VEGF mRNA （P〈0.01）, especially in groups PRS-CTGF-siRNA, and PRS-CTGF-siRNA4. The introduction of PRS void vector did not have these effects （P〉0.05）. Conclusions The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level of CTGF and VEGF induced by TGF-β1 in cultured HPMCs. This study may provide potential therapeutic strategies to prevent the peritoneal fibrosis.

Inhibiting severe acute respiratory syndrome-associated coronavirus by small interfering RNA

OBJECTIVE: To evaluate the effectiveness of small interfering RNA (siRNA) on inhibiting severe acute respiratory syndrome (SARS)-associated coronavirus replication, and to lay bases for the future clinical application of siRNA for the treatment of viral infectious diseases. METHODS: Vero-E6 cells was transfected with siRNA before SARS virus infection, and the effectiveness of siRNA interference was evaluated by observing the cytopathic effect (CPE) on Vero-E6 cells. RESULTS: Five pairs of siRNA showed ability to reduce CPE dose dependently, and two of them had the best effect. CONCLUSION: siRNA may be effective in inhibiting SARS-associated coronavirus replication.

Design of functional small interfering RNAs targeting amyotrophic lateral sclerosis-associated mutant alleles

Background RNA interference （RNAi） is a potential cure for amyotrophic lateral sclerosis （ALS） caused by dominant, gain-of-function superoxide dismutase 1 （SOD1） mutations. The success of such therapy relies on the functional small interfering RNAs （siRNAs） that can effectively deliver RNAi. This study aimed to design the functional siRNAs targeting ALS-associated mutant alleles. Methods A modified dual luciferase system containing human SOD1 mRNA target was established to quantify siRNA efficacy. Coupled with validated siRNAs identified in the literature, we analyzed the rationale of siRNA design and subsequently developed an asymmetry rule-based strategy for designing siRNA. We then further tested the effectiveness of this design strategy in converting a naturally symmetric siRNA into functional siRNAs with favorable asymmetry for gene silencing of SOD1 alleles. Results The efficacies of siRNAs could vary tremendously by one base-pair position change. Functional siRNAs could target the whole span of SOD1 mRNA coding sequence as well as non-coding region. While there is no distinguishable pattern of the distribution of nucleobases in these validated siRNAs, the high percent of GC count at the last two positions of siRNAs （P18 and P19） indicated a strong effect of asymmetry rule. Introducing a mismatch at position 1 of the 5＇ of antisense strand of siRNA successfully converted the inactive siRNA into functional siRNAs that silence SOD1 with desired efficacy. Conclusions Asymmetry rule-based strategy that incorporates a mismatch into siRNA most consistently enhances RNAi efficacy and guarantees producing functional siRNAs that successfully silence ALS-associated SOD1 mutant alleles regardless target positions. This strategy could also be useful to design siRNAs for silencing other disease-associated dominant, gain-of-function mutant genes.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

Suppression of matrix metalloproteinase-2 via RNA interference inhibits pancreatic carcinoma cell invasiveness and adhesion

AIM:To investigate the inhibitory effects of RNA interference (RNAi) on expression of matrix metalloproteinase-2 (MMP-2) gene and invasiveness and adhesion of human pancreatic cancer cell line,BxPC-3.METHODS:RNAi was performed using the vector (pGPU6)-based small interference RNA (siRNA) plasmid gene silence system to specifically knock down MMP-2 expression in pancreatic cancer cell line,BxPC-3. Four groups of different specific target sequence in coding region of MMP-2 and one non-specific sequence were chosen to construct four experimental siRNA plasmids of pGPU6-1,pGPU6-2,pGPU6-3 and pGPU6-4,and one negative control siRNA plasmid of pGPU6 (-). MMP-2 expression was measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation and apoptosis were examined by methyl thiazolyl tetrazolium (MTT) and flow cytometry,respectively. The abilities of adhesion and invasion were detected by cell adhesion assay and cell invasion assay using Transwell chambers.RESULTS:The expression of MMP-2 was inhibited and the inhibitory effects of different sequence varied. pGPU6-1 group had the most efficient inhibitory effect,followed by pGPU6-2 and pGPU6-3 groups.Invasiveness and adhesion were more significantly reduced in pGPU6-1,pGPU6-2 and pGPU6-3 groups as compared with pGPU6 (-) and blank control groups. However,no difference concerning cell proliferation and apoptosis was observed after transfection between experiment groups and control groups.CONCLUSION:RNAi against MMP-2 successfully inhibited the mRNA and protein expression of MMP-2 in the pancreatic cancer cell line,BxPC-3,leading to a potent suppression of tumor cell adhesion and invasion without affecting cell proliferation and apoptosis. These findings suggest that the RNAi approach towards MMP-2 may be an effective therapeutic strategy for the clinical management of pancreatic tumor.