Thyroid-stimulating hormone decreases insulin receptor substrate 1 expression via stimulating TNF-αsecretion in 3T3-L1 adipocytes / 中华内分泌代谢杂志

3T3-L1 adipocytes transfected with TSH receptor (TSHR) shRNA were incubated with bovine TSH.The concentration of tumor necrosis factor (TNF)-α in culture medium was measured by enzyme linked immunosorbent asssy.Protein level of insulin receptor substrate 1 (IRS-1) was quantified by Western blotting.Tyrosine phosphorylation of IRS-1 was measured by immunoprecipitation.The results showed that 1 mIU/ml TSH significantly sitmulated TNF-α release in 3T3-L1 adipocytes [(341.85 ± 12.00 vs 522.67 ± 36.22) ng/L,P＜0.01],along with the decreases in IRS-1 protein expression and its tyrosine phosphorylation (P＜ 0.01).These effects disappeared when TSHR expression was down-regulated with RNA interference in 3T3-L1 adipocytes.In addition,WP9QY,a TNF-α antagonist,blocked TSH-decreased IRS-1 expresssion.These results suggest that TSH downregulates IRS-1 protein expression and its tyrosine phosphorylation through stimulating production of TNF-α,and thus contributes to the development of insulin resistance.

Caspase-8 small hairpin RNA attenuates apoptosis of human bone mar-row mesenchymal stem cells under conditions of serum deprivation and hypoxia / 中国病理生理杂志

AIM:To investigate the effect of caspase-8 small hairpin RNA ( shRNA) on attenuating apoptosis of human mesenchymal stem cells ( hMSCs ) .METHODS: Two recombinant plasmids for over-expression of caspase-8 shRNA, pAd-Cap8 shRNA1 and pAd-Cap8 shRNA2, were constructed.Caspase-8 mRNA was determined in pAd-Cap8 shRNA-transfected human HEK293 cells by Q-PCR.The screened pAd-Cap8 shRNA was used to construct the recombinant adenovirus plasmid , which was linearized and transfected into HEK 293 cells for packaging and amplification of the recombi-nant adenovirus rAd-Cap8 shRNA.The expression of caspase-8 at mRNA and protein levels was determined by Q-PCR and Western blotting .Annexin V/PI staining and determination of caspase-8 activity were performed to assess apoptosis of hM-SCs under the conditions of serum deprivation and hypoxia .The mRNA expression of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1), Bcl-2 and Bcl-xL was analyzed by Q-PCR.RESULTS:The pAd-Cap8 shRNA, which efficiently inhibited caspase-8 expression, was screened by Q-PCR.The recombinant adenovirus plasmid for caspase-8 shRNA was constructed and used to package and amplify the recombinant ad-enovirus ( rAd)-Cap8 shRNA successfully .rAd-Cap8 shRNA-mediated caspase-8 shRNA markedly inhibited caspase-8 ex-pression in hMSCs .Over-expression of caspase-8 shRNA by infection of rAd-Cap8 shRNA also efficiently decreased the ap-optotic rate and caspase-8 activity in hMSCs under the conditions of serum deprivation and hypoxia , with up-regulation of the mRNA expression of HGF, IGF-1 and Bcl-2.CONCLUSION:Caspase-8 shRNA attenuates hMSC apoptosis under the conditions of serum deprivation and hypoxia .

The interference effects on UL29 shRNA expression vectors on HSV-2 / 实用医学杂志

Objective To construct short hairpin RNA (shRNA) recombinant expression vector for herpes simplex virus typeⅡ(HSV-2) UL29 gene and observe its inhibitory effect on HSV-2. Methods Four interference target sites of HSV-2UL29 gene were selected to construct 4 groups of small hairpin RNA respectively,named shRNA recombinant expression vector. The expression vectors were transfected into HEK293 cells with liposome. HEK293 cells were infected with HSV-2 after expression vector being transfected. The viral titer was estimated by end-point titration assay. The level of transcription was estimated by Real-Time PCR method. The expressing effect of protein was detected by Western-blot. Results Recombinant expression vector pGPU6/GFP/Neo-shRNA was constructed successfully. The result of end-point titration assay showed that the viral titer was reduced comparing with blank control (P<0.05). The result of RT-PCR showed that inhibition rates were respectively 28.80%, 59.95%, 66.08%and 36.27% comparing with blank control, and there were significant differences (P < 0.05). The effect of UL29shRNA1461 group was the best one. The result of Western-blot showed that the expressing quantity of ICP8 was reduced. Conclusion Recombinant expression vector pGPU6/GFP/Neo-shRNA can interfere HSV-2 UL29 gene expression from different cell level in vitro, which can inhibit the replication of HSV-2 genome in HEK293 cells. Thus, RNA interference (RNAi) is conducive to the further exploration of viral therapy.

Effect of Small Hairpin RNA Molecules Targeting Angiotensin-converting Enzyme Gene in Spontaneously Hypertensive Rats

BACKGROUND: Interfering RNA (iRNA) represents a recent breakthrough in effective blocking of the target genes in mammalian cells. Angiotensin-converting enzyme (ACE) has been shown to play an important role in the pathogenesis of hypertension. The purposes of this study were to investigate the effects on blood pressure, myocardial hypertrophy and gene expressions of iRNA targeting ACE. METHODS: Twelve week old male Wistar-Kyoto rats were grouped as follows: control group (C group), spontaneously hypertensive rat (SHR) group (H group), and ACE-iRNA group (A group) in which SHR was treated with recombinant lentiviral vectors carrying small hairpin RNA targeting ACE. Reverse transcription-polymerase chain reaction and western blot analysis of ACE, endothelin (ET)-1, angiotensin (AT) II receptor type 1A, neutrophil cytosolic factor, caspase 3, Bax, and Bcl-2 were performed in the heart tissues. Serum AT, ACE, and high sensitive-C reactive protein were estimated. RESULTS: Systolic blood pressure was significantly decreased in the A group compared with the H group in weeks 3 and 5. Serum AT level was significantly lower on day 1, weeks 3 and 5 after ACE-iRNA treatment. ACE protein contents were significantly lower after ACE-iRNA treatment in week 5. ET-1 and Bcl-2 protein contents were significantly lower after ACE-iRNA treatment in weeks 3 and 5. Bax protein contents were significantly lower after ACE-iRNA treatment in week 3. CONCLUSIONS: Recombinant lentiviral vectors carrying shRNA targeting ACE prevented hypertension. Serum AT and gene expressions such as ACE, ET-1, Bax, and Bcl-2 were significantly decreased after ACE-iRNA treatment.

Effect of Small Hairpin RNA Targeting Endothelin-Converting Enzyme-1 in Monocrotaline-Induced Pulmonary Hypertensive Rats

The purpose of this study was to investigate the therapeutic effects of small hairpin RNA (shRNA) targeting endothelin-converting enzyme (ECE)-1 in monocrotaline (MCT)-induced pulmonary hypertensive rats. Ninty-four Sprague-Dawley rats were divided into three groups: control (n = 24), MCT (n = 35) and shRNA (n = 35). Four-week survival rate in the shRNA group was significantly increased compared to that in the MCT group. The shRNA group showed a significant improvement of right ventricular (RV) pressure compared with the MCT group. The MCT and shRNA groups also showed an increase in RV/(left ventricle + septum) ratio and lung/body weight. Plasma endothelin (ET)-1 concentrations in the shRNA group were lower than those in the MCT group. Medial wall thickness of pulmonary arterioles were increased after MCT injection and was significantly decreased in the shRNA group. The number of intra-acinar muscular pulmonary arteries was decreased in the shRNA group. The mRNA expressions of ET-1 and ET receptor A (ETA) were significantly decreased in the shRNA group in week 4. The protein levels of ETA were decreased in the shRNA group in week 2. The protein levels of tumor necrosis factor-alpha and vascular endothelial growth factor were decreased in the shRNA group in week 4. In conclusion, the gene silencing with lentiviral vector targeting ECE-1 could be effective against hemodynamic, histopathological and gene expression changes in pulmonary hypertension.

Effects of the knockdown of hypoxia inducible factor-1alpha expression by adenovirus-mediated shRNA on angiogenesis and tumor growth in hepatocellular carcinoma cell lines / 대한간학회지

BACKGROUND/AIMS: Hypoxia-inducible factor-1alpha (HIF-1alpha) is a central transcriptional factor involved in the cellular responses related to various aspects of cancer biology, including proliferation, survival, and angiogenesis, and the metabolism of the extracellular matrix in hypoxia. This study evaluated whether adenovirus-mediated small hairpin RNA (shRNA) against HIF-1alpha (shHIF-1alpha) inhibits cell proliferation and angiogenesis in hepatocellular carcinoma (HCC) cell lines. METHODS: Knockdown of HIF-1alpha expression was constructed by adenovirus-mediated RNA interference tools, and HCC cell lines infected with shHIF-1alpha coding virus were cultured under a hypoxia condition (1% O2) for 24 hours. Following infection, the expression levels of HIF-1alpha, angiogenesis factors, and matrix metalloproteinase (MMP) were examined using Western blotting. Cell proliferation and angiogenesis were measured by a cell proliferation assay (MTT assay) and an angiogenesis-related assay (invasion and tube-formation assay), respectively. RESULTS: Adenovirus mediated inhibition of HIF-1alpha induced suppression of tumor growth in HCC cell lines. It also down-regulated the expression of angiogenesis factor and MMP proteins. Angiogenesis as well as mobility of vascular cells to tumor was suppressed by adenovirus-mediated shHIF-1alpha-infected groups in human umbilical vein endothelial cells (HUVECs). CONCLUSIONS: These data suggest that adenovirus-mediated inhibition of HIF-1alpha inhibits the invasion, tube formation, and cell growth in HUVECs and HCC cells.

Effect of shRNA Inhibiting HIF1α Gene on TIMP1 Expression in RPE Cells / 华中科技大学学报（医学）（英德文版）

Small hairpin RNA (shRNA) was used to silence the HIF1α gene in human retinal pigment epithelial cells (RPE) under hypoxia in order to observe the effect of gene silencing on the expression of matrix metalloproteinase tissue inhibitor 1 (TIMP1). By using chemical hypoxic inducer CoCl2 to mimic RPE hypoxic environment, shRNA against the targeting region of HIF1α mRNA sequence was synthesized by a method of in vitro transcription, and the HIF1α was interfered in RPE cultured under hypoxia (induced by 150 μmol/L CoCl2 ). RT-PCR was employed to detect the expression of HIF1α and TIMP1. The expression levels of HIF1α and TIMP1 were measured by using Western blotting. The results showed that after the RPE were transfected with specific shRNA against HIF1α mRNA, RT-PCR revealed that under hypoxia, the efficacy of HIF1α gene silencing in RPE was 83. 4 %. Western blotting revealed that the expression levels of HIF1α protein was dramatically dropped. In addition, RT-PCR results demonstrated that the expression of TIMP1 mRNA was decreased by 28.9 %, and the expression levels of TIMP1 protein were also significantly reduced by Western blotting. It was suggested that shRNA targeted against HIF1α mRNA could effectively silence the HIF1α gene, subsequently effectively inhibit the hypoxia-induced up-regulation of TIMP1.

Inhibition of glucosylceramide synthase expression and reversal of multidrug resistance in human breast cancer cells by shRNA / 基础医学与临床

Objective To construct the plasmid containing short hairpin RNA (shRNA) of GCS in order to suppress the expression of GCS and to reverse the multidrug resistance in drug-resistant breast cancer cells. Methods Two reverse repeated motifs of sequence targeting GCS with 6 bp spacer were designed and synthesized in vitro,then they were inserted into the plasmid pSUPER. The recombinant plasmids were transfected into human breast cancer cells. GCS expression was detected by Western blot and immunocytochemistry. caspase-3 expression and its activity were assessed using Western blot and colorimetry,flow cytometry was performed to analyze the ratio of apoptosis. Results MTT method was used to evaluate the 50% inhibition concentration. Enzyme digestion analysis and DNA sequencing confirmed that the recombinant plasmids were successfully constructed. GCS protein content decreased 80%,82% respectively after transfection with recombinant plasmids. The positive rate of GCS expression reduced to 18.1%,16.7% respectively. caspase-3 expression and its activity were significantly higherand the apoptosis of cells increased dramatically. The drug resistance of breast cancer cells to antineoplastic drugs declined significantly. Conclusion shRNA can suppress GCS expression in human drug-resistant breast cancer cells effectively and restore the sensitivity to several antineoplastic drugs.

Effect of RNA interference targeting for cyclin D1 gene on growth,cell cycle and apoptosis of K562 / 中国基层医药

Objective cyclin D1 gene plays a significant role in regulating cell cycle progression.Suppression of cyclin D1 protcin expression can effect on cellular proliferation,distribution of cell cycle and apoptosis.This study was to determine whether this effect also existed in chronic leukemia ceil line K562 by inhibiting the expression of cyclin D1 protein through RNA interference in vetro.Methods Plasmid vectors expressing small hairpin RNA (shRNA) targeting at cyclin D1 gene were constructed and transfected into K562 cells by chitosan,cyclin D1 protein was examined by using Western blot analysis.Inhibition of cellular proliferation was evaluated hy soft agar colony formation assay.The cell cycle and apoptosis were determined by flow cytometry.Results Expression of cyclin D1 protein was markedly down-regulated and capability of colony formation was suppressed after transfection with pshRNA-419 and pshRNA-575 at 48h.Down-regulation of cyclin D1 protein could effect on distribution of cell cycle arrested at G_0/G_1 phase and markedly induce apoptosis of K562 cells.But there had no above biological effects ob- served after transfection with blank vector and control vector of m-pshRNA-790.Conclusion Down-regulation of cyclin D1 expression can inhibit growth of K562 cells,and effect on distribution of cell cycle arrested at G_0/G_1 phase.The primary results suggest that cyclin D1 gene might serve as an effective target for the treatment of leukemia.

RNA Interference in Functional Genomics and Medicine

RNA interference (RNAi) is the sequence-specific gene silencing induced by double-stranded RNA (dsRNA). Being a highly specific and efficient knockdown technique, RNAi not only provides a powerful tool for functional genomics but also holds a promise for gene therapy. The key player in RNAi is small RNA (~22-nt) termed siRNA. Small RNAs are involved not only in RNAi but also in basic cellular processes, such as developmental control and heterochromatin formation. The interesting biology as well as the remarkable technical value has been drawing widespread attention to this exciting new field.

Construction of Skp2 shRNA and its effect on lung cancer cell growth / 第三军医大学学报

Objective To construct and identify the RNAi eukaryotic vector of Skp2 gene and to observe its interfering effect on the growth of SPC-A-1 lung cancer cells.Methods The specific shRNA sequence was designed and synthesized according to the Skp2 cDNA sequence in GenBank.The sequence was cloned into plasmid pGenesil-1.Then recombinant vector was transfected into SPC-A-1 lung cancer cells by Lipofectamine 2000.The expressions of Skp2 mRNA were analyzed by RT-PCR and the levels of Skp2 protein were detected by Western blot.The cell growth suppression was analyzed by MTT assay.Distribution of cell cycle was assessed by flow cytometry.Results The sequence of template and specific siRNA was correct by sequence analysis.Obvious decrease was observed in the levels of Skp2 mRNA and Skp2 protein after Skp2 shRNA transfection(P

Construction of eukaryotic expression vector expressing double shRNA sections targeting Survivin gene in Bx-PC3 cells / 中国临床药理学与治疗学

AIM:To construct eukaryotic expression vector expressing double shRNA sections targeting Survivin gene.METHODS: Eukaryotic expression vector expressing double shRNA sections targeting Survivin gene were designed and chemically synthesized.They were directionally inserted into plasmid pGenesil-1 with respectively U6 promoter and termination code,the common green fluorescence protein(EGFP) gene and Neo gene. In this way,the vector of pGenesil-1 shRNA containing 2 sections of Survivin shRNA were constructed and they were transfected into the pancreatic cancer cell Bx-PC3.Transfection was detected by fluorescence microscope.The inhibition expression of Survivin mRNA was measured by RT-PCR.RESULTS: HE1 and HE2 plasmids were identified by the biocatalyst cut which confirmed the exactitude and were analyzed by the sequence analysis which verified the perfect clone plasmid inserted by them.CONCLUSION: A eukaryotic expression vector of double short hairpin RNA for Survivin gene is successfully constructed.The pancreatic cancer cells Bx-PC3 succeed to be transfected and expression of Survivin mRNA is inhibited obviously.

Effects of SREBP-1 targeted RNAi on lipid droplet formation in HKC cells under stimulation of high glucose / 中国药理学通报

Aim To construct eukaryotic expression vector of shRNA(small hairpin RNA)for human SREBP-1(sterol regulation element binding protein-1)gene and explore its effects on lipid droplet formation in human renal proximal tubular epithelial cell line(HKC)under the stimulation of high glucose.Methods Two eukaryotic expression vectors of shRNA were constructed for human SREBP-1 gene.The HKC cells were transfected with negative control plasmid(pGenesil-1-HK)and two recombinant vectors(pGenesil-1-SREBP1-1 and pGenesil-1-SREBP1-2)and then were cultured under the stimulation of high glucose for about 48 h.The expression of SREBP-1 mRNA and FAS mRNA was detected by RT-PCR and SREBP-1 protein expression was investigated by Western blot.Lipid droplets were detected by Oil Red O staining.Results DNA sequencing showed that the target segments were successfully cloned into pGenesil-1 vector respectively.RT-PCR indicated that two recombinant vectors could inhibit the expression of SREBP-1 mRNA and FAS mRNA in HKC cells under the stimulation of high glucose.Similarly,SREBP-1 protein was also inhibited by the transfection with recombinant vectors.Oil Red O staining found that silencing of SREBP-1 gene resulted in lipid droplets decrease.Conclusions The eukaryotic expression vector of shRNA for human SREBP-1 gene was successfully constructed,and the expression of SREBP-1 was inhibited effectively by the expressed siRNA in HKC cells that resulted in lipid droplets decrease through FAS mRNA transcription inhibition.