The present study was undertaken to investigate the role of glial glutamate transporter-1 (GLT-1) in the brain ischemic tolerance induced by cerebral ischemic preconditioning (CIP) by observing the effect of GLT-1 antisense oligodeoxynucleotides (AS-ODNs) on the neuro-protection of CIP against brain ischemic insult in rats. Wistar rats with permanently occluded bilateral vertebral arteries were randomly assigned to 7 groups: (1) Sham group: the bilateral common carotid arteries (BCCA) were separated, but without occluding the blood flow; (2) CIP group: the BCCA were clamped for 3 min; (3) Brain ischemic insult group: the BCCA were clamped for 8 min; (4) CIP+brain ischemic insult group: 3 min CIP was preformed 2 d prior to 8 min ischemic insult; (5) Double distilled water group: 5 muL double distilled water was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after the BCCA was separated (but without occluding the blood flow), respectively; (6) AS-ODNs group: 5 microL AS-ODNs solution was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after the BCCA was separated (but without occluding the blood flow), respectively. This group was further divided into 9 nmol and 18 nmol subgroups according to the doses of AS-ODNs; (7) AS-ODNs+CIP+brain ischemic insult group: 5 microL AS-ODNs solution was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after CIP, respectively. This group was also further divided into 9 nmol and 18 nmol subgroups according to the doses of AS-ODNs. The other treatments were the same as those in CIP+brain ischemic insult group. The effect of the AS-ODNs on the expression of GLT-1 was assayed by using Western blot analysis. The profile of delayed neuronal death (DND) of pyramidal neurons in the CA1 hippocampus was evaluated by using thionin staining under light microscope by determining the neuronal density (ND) and histological grade (HG). Western blot analysis showed that AS-ODNs injected into the lateral cerebroventricle inhibited the expression of GLT-1 in the CA1 hippocampus in a dose-dependent manner. Neuropathological evaluation showed that there was no apparent DND in sham and CIP groups. Obvious DND of pyramidal neurons was found in brain ischemic insult group, which was represented by an increase in HG and a decrease in ND. CIP effectively protected the pyramidal neurons in the CA1 hippocampus against DND normally induced by ischemic insult, which indicating that CIP induced ischemic tolerance on the pyramidal neurons in the CA1 hippocampus. However, the injection of AS-ODNs into the lateral cerebroventricle blocked the neuro-protection of CIP against DND induced by brain ischemic insult. These results further proved the role of GLT-1 in the brain ischemic tolerance induced by CIP in rats.
Animals ; Brain ; pathology ; Brain Ischemia ; drug therapy ; CA1 Region, Hippocampal ; pathology ; Excitatory Amino Acid Transporter 2 ; metabolism ; Ischemic Preconditioning ; Oligodeoxyribonucleotides ; pharmacology ; Oligonucleotides, Antisense ; pharmacology ; Pyramidal Cells ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo study the effect of phosphorothioate antisense Bcl-xL oligodeoxynucleotides on apoptosis and thermosensitivity of BcaCD885 cells.

METHODSAfter phosphorothioate antisense Bcl-xL oligodeoxynucleotides were transfected into BcaCD885 cells. The characteristics of apoptotic cells were evaluated by morphological observation and TUNEL staining. Apoptotic rate and Bcl-xL protein expression were analyzed with flow cytometry. The influence of phosphorothioate antisense Bcl-xL oligodeoxynucleotides on apoptotic rate of BcaCD885 cells induced by hyperthermia with 43 degrees C 40 min was also examined through flow cytometry.

RESULTSThe BcaCD885 cells transfected with phosphorothioate antisense Bcl-xL oligodeoxynucleotides displayed apoptotic morphological features. The Bcl-xL protein expression level of these cells was down-regulated significantly compared with the controlled group (P < 0.05). The apoptotic rate of these cells induced by hyperthermia was increased significantly compared with the controlled group (P < 0.05).

CONCLUSIONPhosphorothioate antisense Bcl-xL oligodeoxynucleotides can induce apoptosis and improve thermosensitivity of BcaCD885 cells.

Apoptosis ; drug effects ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; drug effects ; genetics ; Hot Temperature ; Humans ; Hyperthermia, Induced ; Mouth Neoplasms ; genetics ; pathology ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; Oligonucleotides, Antisense ; genetics ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Thionucleotides ; pharmacology ; Transfection ; Tumor Cells, Cultured ; bcl-X Protein

The major issue in the development of nucleic acid based therapeutics is the inefficient delivery of these agents into cells. We prepared cholesterol conjugated spermine and evaluated its usefulness as a delivery modality for antisense oligonucleotides in HeLa-Luc cells. A 2'-O-methyl antisense oligonucleotide sequence, designed to correct splicing at an aberrant intron inserted into a normal luciferase reporter gene, was used for complex formation with cholesterol conjugated spermine. Effective delivery of this antisense agent into nucleus would results in the expression of a luciferasereporter gene product. The cholesterol-spermine formed stable complexes with the antisense oligonucleotide and showed modest delivery activity. Furthermore, this delivery activity was maintained even in the presence of serum proteins, mimicking in vivo conditions. Cholesterol-spermine thus has potential as a delivery system for antisense oligonucleotides into cells.
Blood Proteins ; Cholesterol* ; Genes, Reporter ; Introns ; Luciferases ; Oligonucleotides, Antisense ; Spermine*

Despite advances in neurosurgery, radiation, and chemotherapy, the prognosis of patients with malignant brain tumors still remains grim. Considerable efforts have been made to develop new therapeutic strategies for malignant brain tumors. One of the promising new therapies for brain tumors is an intervention at molecular level, and several molecular approaches have been shown to have in vitro and in vivo activities. These include the use of retroviral vectors, herpes simplex viruses, adenoviral vectors in gene transfer, and antisense vectors and oligonucleotides. Preclinical studies of retroviral vector have already been extended to clinical trials, clearly demonstrating the clinical potential of these molecular therapies. Here, I discuss the current status of molecular therapy for brain tumors together with future directions for its development.
Brain Neoplasms* ; Brain* ; Drug Therapy ; Humans ; Neurosurgery ; Oligonucleotides ; Oligonucleotides, Antisense* ; Prognosis ; Simplexvirus ; Zidovudine

OBJECTIVETo test the efficiency of transfecting (99)Tc(m)-labeled anti-miR208b oligonucleotide into early hypertrophic cardiac myocytes in vitro.

METHODSThe anti-oligonucleotide targeting miR208b (AMO) was synthesized and modified with LNA followed by conjugation with N-hydroxysuccinimidyl S-acetyl-meraptoacetyl triglycine (NHS-MAG3) and radiolabeling with (99)Tc(m). NHS-MAG3-LNA-AMO and labeled AMO were purified with Sep-Pak C18 column chromatography, and the former was examined for UV absorption at the 260 nm using Gene Quant DNA/RNA calculator. The labeling efficiency, radiochemical purity, stability and molecular hybridization activity were analyzed. An angiotensin II-induced cell model of hypertrophic cardiac myocytes was transfected with (99)Tc(m)-NHS-MAG3-LNA-AMO via liposome, and the relative expression of miRNA208b and retention ratio of the labeled AMO in early hypertrophic cells were determined.

RESULTSThe labeling efficiency and radiochemical purity of the labeled AMO after purification exceeded 84% and 86%, respectively. The radio- chemical purities of the labeled AMO incubated in serum and normal saline for 12 h were both higher than 80%, and the labeled AMO showed a capacity to hybridize with the target gene. In the hypertrophic model of cardiac myocytes, the retention ratio of labeled AMO at 6 h was higher than 20%.

CONCLUSIONThe (99)Tc(m)-labeled antisense probe can be efficiently transfected into hypertrophic cardiac myocytes in vitro, which provides an experimental basis for subsequent radionuclide imaging studies.

Humans ; Isotope Labeling ; Liposomes ; MicroRNAs ; genetics ; Myocytes, Cardiac ; Oligonucleotides ; Oligonucleotides, Antisense ; Oligopeptides ; Radiopharmaceuticals ; Silicon Dioxide ; Succinimides ; Transfection

With the rapid development of genetic engineering and metabolic regulation, antisense technology displays its fascination to the world as a mild regulation genetic tool. Compared with other loss-of-function research methods (e.g. gene knockout), antisense technologies have advantages such as low cost, short period, and easy operation. It has been increasingly used in bacterial metabolic regulation as a powerful genetic tool. This review briefly summarized the latest progress and problems in antisense technologies that are recently used in metabolic engineering of bacteria, and compares the advantages and disadvantages of these technologies.
Bacteria ; genetics ; metabolism ; Genes, Bacterial ; Genetic Engineering ; Metabolic Networks and Pathways ; genetics ; Oligonucleotides, Antisense ; genetics ; RNA, Antisense ; genetics ; RNA, Catalytic ; genetics

PURPOSE: Aberrant expression of the c-myb gene is often detected in transformed leukemic cells. Inhibition of c-myb expression by antisense oligos could be an effective way to abort rapid growth of leukemic cells. Developing stable antisense oligos combined with enhanced delivery into cells would be of great use in developing an effective anti-cancer molecular agent. MATERIALS AND METHODS: Selection of target sites was carried out by employing computer simulation of mRNA secondary structures. Multiple antisense oligo sequences were adjoined and AS-oligos were then covalently closed to evade exonuclease activities. C-myb antisense oligos with a novel structure were complexed with cationic liposomes and used to treat HL-60 leukemic cells. RESULTS: We developed covalently closed antisense oligos which harbor four adjoined antisense sequences. The c-myb antisense oligos were found to be exceptionally stable and effective in specifically ablating c-myb mRNA. The antisense oligos were able to inhibit growth of leukemic cell line (HL-60) by about 80%. Antisense effect was more pronounced when the cells were treated twice with the antisense oligos at lower concentrations. CONCLUSION: The novel covalently closed antisense oligo (CMAS-oligos) was found to be effective and exceptionally stable, Growth of HL-60 was significantly inhibited, showing a rational way to develop an effective molecular anti-cancer agent.
Cell Line ; Computer Simulation ; Genes, myb ; Liposomes ; Oligonucleotides, Antisense* ; RNA, Messenger

Ceramide induces cell death in a dose- and time-dependent manner in neuroblastoma SK-N-SH cells. To investigate the mechanism of SK-N-SH cell death by C2-ceramide, morphological features and Hoechst 33258 staining were analyzed. In these morphlogic study the cell death by ceramide showed typical apoptotic features, nuclear condensation, fragmentation, and membrane blebbing. Ceramide-induced apoptosis was accompanied by nuclear accumulation of p53. Inhibition of p53 expression with p53 antisense oligonucleotides inhibited apoptosis evoked by ceramide. Also, ceramide induced mitochondrial event, collapse of mitochondrial membrane potential (delta psi m) and interestingly, inhibition of p53 attenuated collapse of mitochondrial membrane potential, suggests that ceramide induces mitochondrial dysfunction through upregulation of p53 expression. These results suggest that ceramide-induced apoptosis is dependent upon increase in cellular p53 levels which play a critical role in the regulation of apoptotic cell death and p53 modulates mitochondrial function such as mitochondrial membrane potential level.
Apoptosis ; Bisbenzimidazole ; Blister ; Cell Death* ; Membrane Potential, Mitochondrial ; Membranes ; Neuroblastoma ; Neurons* ; Oligonucleotides, Antisense ; Up-Regulation

DNA, Viral ; genetics ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; Humans ; Oligonucleotides, Antisense ; pharmacology

Duchenne muscular dystrophy (DMD) is a lethal muscular disorder caused by mutations in the dystrophin gene for which no mutation targeted therapy has been available so far. However, a new method named exon-skipping mediated by antisense oligonucleotides has considerable potential for DMD therapy. In this review, the principle, basic research and clinical research of exon-skipping are mainly summarized.
Animals ; Exons ; genetics ; Humans ; Muscular Dystrophy, Duchenne ; genetics ; therapy ; Oligonucleotides, Antisense ; genetics