Fragmented hyaluronan induces transcriptional up-regulation of the multidrug resistance-1 gene in CD4+ T cells

P-glycoprotein, encoded by the multidrug resistance (MDR)-1 gene, expels various drugs from cells resulting in multidrug resistance. We found previously that interleukin-2, a lymphocyte-activation cytokine, induces P-glycoprotein expression on lymphocytes. Lymphocyte activation involves adhesion with the extracellular matrix, such as hyaluronan, through adhesion molecules on lymphocytes. We investigated the transcriptional regulation of MDR-1 in lymphocytes by fragmented hyaluronan. Fragmented hyaluronan (especially the 6.9-kDa form), not native high molecular hyaluronan, induced translocation of YB-1, a specific transcriptional factor for MDR-1, from the cytoplasm into the nucleus and resulted in the transcription of MDR-1 and the expression of P-glycoprotein on lymphocytes in a dose-dependent manner. Transfection of YB-1 antisense oligonucleotides inhibited P-glycoprotein expression induced by fragmented hyaluronan. The fragmented hyaluronan induced significant P-glycoprotein expression on only activated CD4+ T cells, which highly expressed CD69, and resulted in excretion of intracellular dexamethasone added in vitro. Cyclosporin A, a competitive P-glycoprotein inhibitor, restored intracellular dexamethasone levels in CD4+ T cells. Anti-CD44 monoclonal antibody (Hermes-1) inhibited fragmented hyaluronan-induced YB-1 activation and P-glycoprotein expression in CD4+ T cells. We provide the first evidence that binding of fragmented hyaluronan to CD44 induces YB-1 activation followed by P-glycoprotein expression in accordance with activation of CD4+ T cells. Our findings imply that CD4+ T cell activation by fragmented hyaluronan, induced by characteristic extracellular matrix changes in inflammation, tumors, and other conditions, results in P-glycoprotein-mediated multidrug resistance.

Superoxide dismutase as a target enzyme for Fe-porphyrin-induced cell death

The cell viability of human cancer cell lines treated with [5,10-bis(N-methyl-4-pyridyl)-15,20-diphenyl]porphinatoiron(III) (cis-FeMPy(2)P(2)P) has been estimated. The cis-FeMPy(2)P(2)P is a superoxide dismutase (SOD) mimic in vitro that exhibited a significant toxicity in cancer cell lines. This toxicity is rather due to pro-oxidant properties of the iron-porphyrin in vivo. We have demonstrated that there was the relationship between the LD(50) values calculated from the viability of cancer cell lines treated with cis-FeMPy(2)P(2)P and the SOD activities of the cell lines. Furthermore, the inhibition of SOD by antisense S-oligonucleotide increased the cytotoxic effect of cis-FeMPy(2)P(2)P against cancer cells. These results suggest that SOD is a target enzyme for the cell death induced by cis-FeMPy(2)P(2)P as a new class of anticancer agents.

Tbx16 cooperates with Wnt11 in assembling the zebrafish organizer

The organizer, the signaling center that specifies vertebrate axial polarity and the nervous system, is a dorsal midline mesodermal domain in the gastrula that will form prechordal plate and anterior notochord. We show that in zebrafish the organizer is not a single domain when it first arises in the nascent mesoderm at the onset of gastrulation. Rather, in the presumptive prechordal plate region, the organizer is subdivided into two side-by-side cellular fields. Within minutes, concurrent medial and anterior cellular movements merge, or 'coalesce', the two fields to form the well-known singular midline field. Coalescence forms a symmetrical domain because the cell movements on the left and right sides initiate simultaneously and occur synchronously. However, in embryos with reduced function of the T-box transcription factor Tbx16 (Spadetail) or its genetic target paraxial protocadherin (Papc), synchrony is lost, coalesence is disrupted, and the midline domain is misshaped. Furthermore, with combined loss of Tbx16 and Wnt11 (Silberblick), coalesence is essentially absent. Possibly as a consequence, both the anterior movement of presumptive prechordal plate and organizer function, as assayed by eye-field separation, are disrupted. Our findings thus reveal that Tbx16, in combination with Wnt11, are critical components not only in morphogenesis but also in initial assembly of the organizer.

Dissociation of Crk-associated substrate from the vimentin network is regulated by p21-activated kinase on ACh activation of airway smooth muscle

The intermediate filament protein vimentin has been shown to be required for smooth muscle contraction. The adapter protein p130 Crk-associated substrate (CAS) participates in the signaling processes that regulate force development in smooth muscle. However, the interaction of vimentin filaments with CAS has not been well elucidated. In the present study, ACh stimulation of tracheal smooth muscle strips increased the ratio of soluble to insoluble vimentin (an index of vimentin disassembly) in association with force development. ACh activation also induced vimentin phosphorylation at Ser(56) as assessed by immunoblot analysis. More importantly, CAS was found in the cytoskeletal vimentin fraction, and the amount of CAS in cytoskeletal vimentin was reduced in smooth muscle strips on contractile stimulation. CAS redistributed from the myoplasm to the periphery during ACh activation of smooth muscle cells. The ACh-elicited decrease in CAS distribution in cytoskeletal vimentin was attenuated by the downregulation of p21-activated kinase (PAK) 1 with antisense oligodeoxynucleotides. Vimentin phosphorylation at this residue, the ratio of soluble to insoluble vimentin, and active force in smooth muscle strips induced by ACh were also reduced in PAK-depleted tissues. These results suggest that PAK may regulate CAS release from the vimentin intermediate filaments by mediating vimentin phosphorylation at Ser(56) and the transition of cytoskeletal vimentin to soluble vimentin. The PAK-mediated dissociation of CAS from the vimentin network may participate in the cellular processes that affect active force development during ACh activation of tracheal smooth muscle tissues.

Inhibition of coxsackievirus B3 in cell cultures and in mice by peptide-conjugated morpholino oligomers targeting the internal ribosome entry site

Coxsackievirus B3 (CVB3) is a primary cause of viral myocarditis, yet no effective therapeutic against CVB3 is available. Nucleic acid-based interventional strategies against various viruses, including CVB3, have shown promise experimentally, but limited stability and inefficient delivery in vivo remain as obstacles to their potential as therapeutics. We employed phosphorodiamidate morpholino oligomers (PMO) conjugated to a cell-penetrating arginine-rich peptide, P007 (to form PPMO), to address these issues. Eight CVB3-specific PPMO were evaluated with HeLa cells and HL-1 cardiomyocytes in culture and in a murine infection model. One of the PPMO (PPMO-6), designed to target a sequence in the 3' portion of the CVB3 internal ribosomal entry site, was found to be especially potent against CVB3. Treatment of cells with PPMO-6 prior to CVB3 infection produced an approximately 3-log(10) decrease in viral titer and largely protected cells from a virus-induced cytopathic effect. A similar antiviral effect was observed when PPMO-6 treatment began shortly after the virus infection period. A/J mice receiving intravenous administration of PPMO-6 once prior to and once after CVB3 infection showed an approximately 2-log(10)-decreased viral titer in the myocardium at 7 days postinfection and a significantly decreased level of cardiac tissue damage, compared to the controls. Thus, PPMO-6 provided potent inhibition of CVB3 amplification both in cell cultures and in vivo and appears worthy of further evaluation as a candidate for clinical development.

[Echogenic phospholipids-based gas-filled microbubbles as delivery system of antisense oligodeoxynucleotides]

AIM

To investigate the feasibility of transfer antisense oligodeoxynucleotides (AS-ODNs) by the phospholipids-based gas-filled microbubbles (PGM) under ultrasound activation.

METHODS

An antisense oligodeoxynucleotides sequence ZL combined with luciferase reporter plasmid was used. A breast cancer cell line SK-BR-3 was exposed to different conditions to investigate the effects of such factors as ZL concentration, PGM concentration, mechanical index (MI) and ultrasound exposure duration on transfection efficiency and cell viability. The transfection efficiency and cell viability by other lipid vectors such as lipofectamine and liposome were also tested, whose results were comparied with that of PGM. Transfection efficiency was detected by fluorescence microscopy. Cell viability was verified by PI (propidium iodide) assay.

RESULTS

Among the factors tested, ultrasound exposure duration, MI and PGM concentration had obvious impacts on transfection efficiency and cell viability. The results showed that the optimal ultrasound condition was the exposure to ultrasound at MI 1.0 for 30 s with 2% PGM concentration, which gave an overall transfection efficiency of 78% +/- 10%, increased nearly 18 folds over the transfection by PGM (4.0%) or lipofectamine (4.3%) without ultrasound. Under same ultrasound conditions, different vectors showed significant difference in transfection efficiency while there are similar results in cell viability.

CONCLUSION

Under proper ultrasound conditions, PGM can markedly enhance AS-ODNs transfection efficiency.

[Inhibitory effects of antisense MMP-9 oligodeoxynucleotides on invasiveness and adherence of ovarian cancer cells]

OBJECTIVE

To observe the inhibitory effects of antisense MMP-9 oligodeoxynucleotides on invasiveness and adhesion ability in vitro of ovarian cancer cells, and to investigate the mechanisms of action.

METHODS

MMP-9 antisense oligonucleotides were transfected by lipofectinmin into ovarian cancer cell line HO-8910PM cells expressing MMP-9 induced with fibronectin. RT-PCR, Western blot and gelatin zymography were used to detected MMP-9 expression of mRNA and protein and enzymatic activity. The ability of invasion and migration of ovarian cancer cells was assayed in Transwell cell culture chamber. Cell adhersion assay was carried out in a microculture well pre-coated with fibronectin.

RESULTS

MMP-9 expressions of mRNA and protein were significantly decreased in the antisense-transfected cells. Comparing with the control group, the inhibition rate was 34. 8% and 42. 5% , respectively (P <0. 05). Its gelatin enzymatic activity was inhibited. Matrigel invasion assay and Transwell migration assay revealed markedly reduction in invasion and migration for the antisense group. The inhibition rates were 22. 4% and 24. 8% , respectively. The adhesion ability was also reduced. The inhibition rates were 49. 8% and 38. 3% at 60 min and 90 min, respectively.

CONCLUSION

MMP-9 down-regulation can significantly inhibit the ability of invasion and attachment of ovarian cells in vitro. MMP-9 may play an important role in invasion and metastasis of ovarian cells and potentially be a molecular target of blocking invasion and metastasis of ovarian cancer.

XGAP, an ArfGAP, is required for polarized localization of PAR proteins and cell polarity in Xenopus gastrulation

To dissect the molecular mechanisms underlying convergent extension (CE), a prominent set of cell movements during Xenopus gastrulation, we performed a functional expression screen and identified a GTPase-activating protein for ADP ribosylation factors (ArfGAP), which we termed XGAP. We demonstrated that XGAP is required to confine or restrict the cellular protrusive activity to the mediolateral ends of cells, where XGAP is normally localized, and therefore for the proper intercalation of cells participating in CE. We also demonstrated that a C-terminal conserved domain of XGAP, but not its GAP activity, is required and sufficient for this intracellular localization and function. We further showed that XGAP physically interacts with the known polarity proteins 14-3-3epsilon, aPKC, and PAR-6 and directs them to the mediolateral ends of dorsal mesoderm cells during gastrulation. We propose that XGAP controls CE through the restriction and maintenance of partitioning-defective (PAR) proteins in the regions that harbor protrusive activity.

Circadian gene mPer2 overexpression induces cancer cell apoptosis

The Period2 gene, an indispensable component of the circadian clock, not only modulates circadian oscillations, but also regulates organic function. We examined whether overexpression of the mouse Period2 gene (mPer2) in tumor cells influences cell growth and induces apoptosis. Overexpression of PERIOD2 in the mouse Lewis lung carcinoma cell line (LLC) and mammary carcinoma cell line (EMT6) results in reduced cellular proliferation and rapid apoptosis, but not in NIH 3T3 cells. Overexpressed mPER2 also altered the expression of apoptosis-related genes. The mRNA and protein levels of c-Myc, Bcl-X(L) and Bcl-2 were downregulated, whereas the expression of p53 and bax was upregulated in mPER2-overexpressing LLC cells compared with control cells transferred with empty plasmid. Our results suggest that the circadian gene mPeriod2 may play an important role in tumor suppression by inducing apoptotic cell death, which is attributable to enhanced pro-apoptotis signaling and attenuated anti-apoptosis processes.

Msx1 and Msx2 have shared essential functions in neural crest but may be dispensable in epidermis and axis formation in Xenopus

The homeodomain factors Msx1 and Msx2 are expressed in essentially identical patterns in the epidermis and neural crest of Xenopus embryos during neurula stages. Disruption of Msx1 and Msx2 RNA splicing with antisense morpholino oligonucleotides shows that both factors are also required for expression of the neural crest gene Slug. Loss of Msx1 can be compensated by overexpression of Msx2 and vice versa. Loss of Msx factors also leads to alterations in the expression boundaries for neural and epidermal genes, but does not prevent or reduce expression of epidermal keratin in ventrolateral ectoderm, nor is there a detectable effect on dorsal mesodermal marker gene expression. These results indicate that Msx1 and Msx2 are both essential for neural crest development, but that the two genes have the same function in this tissue. If Msx genes have important functions in epidermis or axial mesoderm induction, these functions must be shared with other regulatory proteins.

The microtubule-severing protein Spastin is essential for axon outgrowth in the zebrafish embryo

Hereditary spastic paraplegia (HSP) is a collection of neurological disorders characterized by developmental failure or degeneration of motor axons in the corticospinal tract and progressive lower limb spasticity. SPG4 mutations are the most common cause of autosomal dominant HSP and Spastin (the SPG4 gene product) is a microtubule severing protein that shares homology with katanin, the microtubule severing activity of which promotes axon growth in cultured neurons. Given the sequence and functional similarity between spastin and katanin, we hypothesized that spastin promotes the dynamic disassembly and remodelling of microtubules required for robust, properly directed motor axon outgrowth. To investigate this hypothesis, we cloned the zebrafish spg4 orthologue and used morpholino antisense oligonucleotides directed against the translation start site and the intron 7-8 splice donor site to knock down spastin function in the developing zebrafish embryo. Reduced spg4 function caused dramatic defects in motor axon outgrowth without affecting the events driving the initial specification of motor neurones. Other neuronal subtypes also exhibited a requirement for spg4 function, since spg4 knock down caused both widespread defects in neuronal connectivity and extensive CNS-specific apoptosis. Our results reveal a critical requirement for spastin to promote axonal outgrowth during embryonic development, and they validate the zebrafish embryo as a novel model system to dissect the pathogenetic mechanisms underlying HSP. Taken together with other recent studies, our findings suggest that axon outgrowth defects may be a common feature of childhood SPG3A and SPG4 cases.

Functional characterization of the Bcl-2 gene family in the zebrafish

Members of the Bcl-2 protein family control the intrinsic apoptosis pathway. To evaluate the importance of this family in vertebrate development, we investigated it in the zebrafish (Danio rerio). We found that the zebrafish genome encodes structural and functional homologs of most mammalian Bcl-2 family members, including multi-Bcl-2-homology (BH) domain proteins and BH3-only proteins. Apoptosis induction by gamma-irradiation required zBax1 and zPuma, and could be prevented by overexpression of homologs of prosurvival Bcl-2 family members. Surprisingly, zebrafish Bax2 (zBax2) was homologous to mammalian Bax by sequence and synteny, yet demonstrated functional conservation with human Bak. Morpholino knockdown of both zMcl-1a and zMcl-1b revealed their critical role in early embryonic zebrafish development, and in the modulation of apoptosis activation through the extrinsic pathway. These data indicate substantial functional similarity between zebrafish and mammalian Bcl-2 family members, and establish the zebrafish as a relevant model for studying the intrinsic apoptosis pathway.

[Caspase-3 antisense oligodeoxynucleotides inhibit caspase-3 expression and apoptosis of gamma-irradiated HL-60 cells]

It has been shown that gamma -irradiation induces apoptosis of the human promyeloid leukemia cell line HL-60, but the mechanism remains unclear. To explore the effect of caspase-3 in this apoptotic model, antisense oligodeoxynucleotides (ASODNs) targeting 5'-noncoding region (ASODN-1) and initial translation region (ASODN-2) of caspase-3 mRNA were designed, synthesized and introduced into HL-60 cells by means of liposome-mediated transfection followed by gamma-irradiation in the present study. The TUNEL assay was used for morphological analysis of HL-60 cell apoptosis. Immunocytochemical staining, Western blotting and RT-PCR were, respectively, performed for detecting expression of caspase-3 and its mRNA. HL-60 cells transfected with mismatched oligodeoxynucleotide (MODN) or untransfected were taken as the control groups. The TUNEL assay showed that the percentages of HL-60 cell apoptosis induced by gamma-Irradiation in both ASODN-1 and ASODN-2 groups were significantly reduced compared with those in the control group (P<0.01) when the final transfection concentration was > or = 3 micromol/L. Immunocytochemistry demonstrated that in the ASODN-1 and ASODN-2 groups, caspase-3 positive cell percentages were reduced and average gray values of the positive cells increased significantly compared with those in the control group (P<0.01). Western blotting found that procaspase-3 expression in HL-60 cells of the ASODNs groups was decreased,and it was lower in the ASODN-1 group than in the ASODN-2 group. RT-PCR revealed marked expression of caspase-3 mRNA in HL-60 cells of the control group. Expression of caspase-3 mRNA was decreased after ASODNs transfection. Furthermore, ASODN-1 was more effective in inhibiting HL-60 cell apoptosis (P<0.05) and caspase-3 expression (P<0.01) than ASODN-2. These results indicate that caspase-3 mRNA ASODNs prevent HL-60 cells from apoptosis induced by gamma-radiation,and reduce expression of caspase-3 and its mRNA. These effects are dose dependent in a certain range.

Design and screening of antisense oligodeoxynucleotides against PAI-1 mRNA in endothelial cells in vitro

AIM

To design and screen antisense oligodeoxynucleotides (ASODNs), which inhibit type-1 plasminogen activator inhibitor (PAI-1) expression in human umbilical vein endothelial cells (HUVEC) in vitro.

METHODS

Twenty seven ASODNs against different sites of PAI-1 mRNA were designed and transfected to HUVEC by lipofectin in vitro. The effects of ASODNs on PAI-1 antigen, PAI-1 activity and PAI-1 mRNA expression were detected by ELISA, amidolytical assay and RT-PCR, respectively.

RESULTS

Transforming growth factor beta1 (TGF-beta1)-treated HUVEC increased the expression of PAI-1 compared with the normal HUVEC. Five among twenty seven designed ASODNs were effective in inhibiting the increase in PAI-1 antigen and PAI-1 activity in a dose-dependent manner after 48-h transfection. In particular, ASODN 14 (AO14) exhibited the best inhibitory effect. The control sequences of AO14, including sense, scramble, and mismatch sequences, did not significantly inhibit PAI-1 activity. It was revealed that the inhibitory efficacy of AO14 was in a sequence-specific manner. RT-PCR showed that ASODN 1, 7, 8, 14, and 15 decreased PAI-1 mRNA expression induced by TGF-beta1 and AO14 showed the best inhibitory effect.

CONCLUSION

ASODN 1, 7, 8, 14, and 15, among twenty seven designed ASODNs against PAI-1 mRNA, significantly decreased PAI-1 antigen and PAI-1 activity induced by TGF-beta1 in a dose-dependent manner in HUVEC in vitro. AO14 showed the best inhibitory effect on PAI-1 expression in a sequence-specific manner. The results of RT-PCR indicated that inhibitory effects of ASODNs on PAI-1 biosynthesis occurred at the mRNA level. Four among five effective target sites of ASODNs located at the translation initiation site or within the translation area of PAI-1 mRNA, suggesting that these sites may be promising sites for the design of effective ASODNs.

Identification and characterization of syntaxin 1 antisense variants in Limulus polyphemus

1.A Limulus SMART(TM) cDNA library screening resulted in the cloning of four syntaxin 1 homologs (referred to as Limulus syntaxin [Lim-syn] 1A, 1B, 1C, and 1D) (Wang, Y., Cao, Z., Xu, W., Kemp, M. D., McAdory, B. S., Newkirk, R. F., Ivy, M. T., and Townsel, J. G. (2004). Gene 326:189-199) and two novel intron-retaining syntaxin 1-like variants, designated Limulus syntaxin variant [Lim-synV] 1A/1C and Lim-synV 1B/1D. 2.The variants exhibited high amino acid sequence identity with the four syntaxin 1 homologs. Specifically, Lim-synV 1A/1C and Lim-synV 1B/1D were homologous to Lim-syn 1A/1C and Lim-syn 1B/1D, respectively. Surprisingly, both Lim-synV 1A/1C and 1B/1D are unusual in that each has a poly A+ tail, an intron, and the common splice motif "GT-AG" at the intron-exon boundary. Exons one and two on the complementary transcript of Lim-synV 1B/1D are separated by a 150 bp intron beginning at #95/96 of the predicted sequences for Lim-syn 1B and 1D, respectively. 3. In contrast, examination of the approximately 3.17 kb Lim-synV 1A/1C clone indicated the inclusion of an insert of 1120 base pairs (bp) beginning at codon #37/38 of the predicted Lim-syn 1A and 1C cDNAs' open reading frames (ORFs). Further, the intron sequence of Lim-synV 1A/C contained multiple stop codons and showed no significant homology to other known sequences as determined by a search of the GenBank database. Thus, the focus of this paper will be Lim-synV 1B/D exclusively. 4. To substantiate that an intron is retained in the full-length mRNA, two types of syntaxin cDNA fragments for Lim-syn 1B/D were generated by RT-PCR and analyzed on Northern blots. The products generated were a mixture of intron-retaining, as well as intron-spliced products. The syntaxin-like variants that retained the intron presumably are derived from a mRNA molecule that has not undergone splicing.5. Although the significance of such intron-containing mRNAs in Limulus has not yet been elucidated, future studies of such variants may serve to broaden our knowledge concerning established splicing mechanisms as well as to focus attention on nonconventional concepts about gene product regulation.

Expression of mouse osteoclast K-Cl Co-transporter-1 and its role during bone resorption

To assess the role of Cl- transport during osteoclastic bone resorption, we studied the expression and function of K+/Cl- co-transporters (KCCs). KCC1 and chloride channel-7 were found to be expressed in mouse osteoclasts. The KCC inhibitor, R(+)-butylindazone (DIOA), KCC1 antisense oligo-nucleotides, and siRNA suppressed osteoclastic pit formation. DIOA also decreased Cl- extrusion and reduced H+ extrusion activity. These results show that KCC1 provides a Cl- extrusion mechanism accompanying the H+ extrusion during bone resorption.

INTRODUCTION

Mice with deficient chloride (Cl-) channels, ClC7, show severe osteopetrosis, resulting from impairment of Cl- extrusion during osteoclastic bone resorption. However, the expression and functional role of Cl- transporters other than ClC7 in mammalian osteoclasts is unknown. The aim of this study was to determine expression of K+/Cl- co-transporters (KCCs) and their functional role for bone resorption in mouse osteoclasts.

MATERIALS AND METHODS

Mouse osteoclasts were derived from cultured bone marrow cells with macrophage-colony stimulating factor (M-CSF) and RANKL or from co-culture of bone marrow cells and primary osteoblasts. We examined the expression of Cl- transporters using RT-PCR, immunochemical, and Western blot methods. The effects of Cl- transport inhibitors on H+ and Cl- extrusion were assessed by measuring intracellular H+ ([H+]i) and Cl- ([Cl-]i). The effects of inhibitors, antisense oligo-nucleotides, and siRNA for Cl- transporters on bone resorption activities were evaluated using a pit formation assay.

RESULTS AND CONCLUSIONS

Mouse osteoclasts express not only ClC7 but also K+/Cl- co-transporter mRNA. The existence of KCC1 in the cell membrane of mouse osteoclasts was confirmed by immunochemical staining and Western blot analysis. KCC inhibitors and Cl- channels blockers increased [Cl-]i and [H+]i in resorbing osteoclasts, suggesting that the suppression of Cl- extrusion through KCC and Cl- channels leads to reduced H+ extrusion activity. The combination of both inhibitors greatly suppressed these extrusion activities. KCC inhibitors and Cl- channel blockers also decreased osteoclastic bone resorption in our pit area essay. Furthermore, KCC1 antisense oligo-nucleotides and siRNA suppressed osteoclastic pit formation as well as treatment of ClC7 inhibitors. These results indicate that K+/Cl- co-transporter-1 expressed in mouse osteoclasts acts as a Cl- extruder and plays an important role for H+ extrusion during bone resorption.

Anxiolytic effect and memory improvement in rats by antisense oligodeoxynucleotide to 5-hydroxytryptamine-2A precursor protein

Serotonergic (5-hydroxytryptamine; 5-HT) mechanisms have been implicated in a number of physiological and pathophysiological processes including mood, anxiety, and cognitive functioning. Among the many 5-HT receptor subtypes, the 5-HT2A receptors (5-HT2A-R) seem to be of particular importance in mediating these effects, and they are prime targets for a variety of psychoactive substances-from hallucinogenic drugs, through atypical antipsychotics, to anxiolytics and antidepressants. Various selective 5-HT2A-R ligands induce different behavioral responses. To determine whether receptor downregulation is an essential part of anxiolytic action, levels of 5-HT2A receptors were manipulated in rats using a nonpharmacological approach-by the administration of an antisense oligodeoxynucleotide (ASODN) to 5-HT2A-R. Each ASODN was injected icv between two and five times at 24-hr intervals. Control rats received injections of either a scrambled oligodeoxynucleotide (ScrODN) or the vehicle only. On Day 6, anxiety-related behavior was assessed in the elevated plus maze paradigm and performance of memory tasks in the Morris water maze. Gene transcripts were measured by quantitative reverse transcription polymerase chain reaction (PCR). The results show that compared to vehicle and ScrODN control animals, icv 5-HT2A-R-ASODN administrations for 4 consecutive days (but not less) significantly decreased anxietylike behavior and improved memory retention performance. The reduction in anxiety-related behavior in 5-HT2A-R-ASODN rats was accompanied by a decrease in 5-HT2A-R-mRNA expression in the frontal cortex and in the hippocampus. Receptor downregulation has been proposed as one of the central mechanisms for anxiolytic drug actions. Antisense-mediated downmanipulation of receptors in this study, especially of 5-HT2A, supports this theory.

E1A is the component of the MHC class I enhancer complex that mediates HDAC chromatin repression in adenovirus-12 tumorigenic cells

In adenovirus-12 tumorigenic cells, the viral E1A-12 protein mediates transcriptional down-regulation of the major histocompatibility complex (MHC) class I genes by targeting the class I enhancer. Here, we demonstrate by a combination of antisense and chromatin immunoprecipitation (ChIP) analysis that E1A-12 is a physical component of the class I enhancer repression complex, known to comprise COUP-TFII and histone deacetylase 1 (HDAC1). Significantly, E1A antisense was shown to co-eliminate E1A-12 as well as HDAC1 and HDAC8, but not HDAC3, from the enhancer repression complex. Consistent with elimination of HDAC1 and HDAC8, E1A antisense also resulted in a dramatic increase in histone acetylation, a hallmark of transcriptionally active chromatin. Importantly, MHC class I antigen expression was restored on the surface of E1A antisense-transfected cells. These results demonstrate that E1A-12 is associated with the MHC class I complex and apparently mediates class I transcriptional down-regulation by enacting chromatin repression through HDAC1 and HDAC8.

AgeWa: an integrated approach for antisense experiment design

One of the major fallouts of the human genome project relates to the investigation of the molecular mechanisms of diseases. Identification of genes which are involved in a specific pathological process and characterization of their interactions is of fundamental importance for supporting the drug design processes. Discovery of targets and the related experimental validation is a critical step in the development of new drugs. The new experimental methods for gene expression analysis, such as microarray technology, allows for the concurrent evaluation of the expression of multiple genes. The outcome of these new experimental methods requires a subsequent validation of the gene function by using in vitro or in vivo models. In the last decade, one of the most promising methodologies for the investigation of gene function relies upon antisense oligonucleotides (ASO). The crucial step in antisense experiment design is the characterization of the nucleotide domains that can efficiently be targeted by this kind of synthetic molecule. At present, no standardized procedures for target selection are available. In this paper, we propose an integrative approach to ASO target selection: the proposed tool Automatic Gene Walk (AgeWa) combines a neural filter with database mining for the prediction of the optimal target for antisense action.

[Effect of down-regulation of survivin gene on apoptosis and cisplatin resistance in cisplatin resistant human lung adenocarcinoma A549/CDDP cells]

OBJECTIVE

To investigate the effects of survivin antisense oligodeoxynucleoties (ASODN) transfection mediated by cytofectin on apoptosis and cisplatin resistance in cisplatin resistant human lung adenocarcinoma A549/CDDP cells in vitro.

METHODS

A549/CDDP cells were cultured routinely in RPMI-1640 medium. Survivin ASODN mediated by cytofectin was transfected into the A549/CDDP cells. Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry SABC assays were performed to determine the regulation of survivin expression by ASODN. The influence of ASODN transfection on apoptosis was determined by fluoroscence microscopy and Hoechst staining, agarose gel electrophoresis, flow cytometry and caspase-3 colorimetric assay. MTT assay was performed to detect the cell viability, half-maximum inhibitory concentration (IC50) and cisplatin resistance index (RI) were thereby calculated.

RESULTS

Transfected by survivin ASODN for 48 h, down-regulation of survivin expression was measured, of which mRNA and protein expression was significantly down-regulated to 41.56% and 0.864 +/- 0.045, respectively (P < 0.05). Transfection with survivin ASODN caused typical apoptotic changes, including characteristic chromatin condensation, nuclear shrinkage, nuclear cleavage and the cells grew more regularly, and some cells were floating. Typical DNA ladder pattern was observed by agarose gel electrophoresis. Furthermore, apoptotic index and caspase-3 activity was enhanced to 34.03% and 1.1298 +/- 0.2502, respectively (P < 0.05). It was significantly different as compared with the control group. While combination with ASODN and 10 micromol/L cisplatin caused far more distinctive apoptotic alterations, of which AI and caspase-3 activity reached to 65.85% and 1.6805 +/- 0.2758, respectively (P < 0.05), and even compared with the single ASODN group, the difference was still significant (P < 0.05). Transfected with survivin ASODN only or with combination of cisplatin for 48 h, the inhibitory rate of cell growth was enhanced to 59.3% and 83.7% (P < 0.05), respectively, while inversely, the cell viability reduced to a lowest value. The half-maximum inhibitory concentration of cisplatin was reduced from 225.03 +/- 10.59 micromol/L to 158.84 +/- 4.26 micromol/L, and the resistant index was conversely reduced from 11.9 to 8.39. Non-sense oligodeoxynucleotides (NSODN) and liposome had no effect on the cells growth (P > 0.05).

CONCLUSION

Transfection with survivin ASODN can to a great extent reverse the cisplatin resistance in human cisplatin resistant lung adenocarcinoma cells A549/CDDP in vitro, and can thereby significantly inhibit the growth of the cells. The mechanism of reversal of resistance to cisplatin by this transfection can be associated with specific down-regulation of survivin expression, which decreases the threshold of apoptosis, induces more pronounced apoptosis,and reverses the resistance to apoptosis induced by cisplatin in A549/CDDP cells in vitro.

[Molecular mechanism of anti-apoptotic action of survivin in NCI-H446 lung cancer cells]

OBJECTIVE

To investigate cell apoptosis induced by survivin ASODN and clarify the precise mechanism of anti-apoptotic action of survivin.

METHODS

Cells of lung cancer cell line NCI-H446 were treated with survivin ASODN at different concentrations. The changes of survivin mRNA and protein expression were assessed by RT-PCR and Western blot assay. The apoptosis index (AI) and proliferation index (PI) were determined by flow cytometry (FCM). After 500 mmol/L survivin ASODN treatment, cells were stained with Rh123 to detect changes of mitochondrial membrane potential (deltapsim) by FCM. The concentration of cytoplasmic cytochrome c (cyt-c) was continuously determined by ELISA. Relative activities of caspase-9 and caspase-3 were assessed by colorimetric assay. The expression of caspase-8 protein was measured by Western blot assay. The apoptotic rates of lung cancer cells induced by survivin ASODN with or without mitochondrial permeability transition pole (MPTP) inhibitor CsA treatment were assessed by FCM.

RESULTS

Down-regulated survivin mRNA was shown to be in dose-dependent and time-dependent manners. Its maximal effect was achieved at a concentration of 500 nmol/L for 72 h, at which mRNA was down-regulated by 62.7%, the expression of survivin protein in NCI-H446 cells was also obviously decreased. After treatment with survivin ASODN at concentration of 500 mmol/L for 72 h, AI was 48.35%, higher than that of control, lipofectin, NSODN, survivin ASODN 100 mmol/L and 300 mmol/L groups (3.75%, 3.41%, 4.69%, 19.85% and 34.39%, respectively). PI was 24.38%, lower than that of control, lipofectin, NSODN, survivin ASODN100 and 300 mmol/L groups (75.74%, 73.12%, 71.76%, 51.03% and 38.94%, respectively). Deltapsim was decreased in 9.54% of NCI-H446 cells treated with survivin ASODN for 3 h and 97.06% for 24 h. Following it, release of cyt-c from mitochondria to cytosol and activation of caspase-9 and caspase-3 increased significantly. The above mentioned indicators changed with a time-dependent and time diversity relationship. In the presence of CsA, the apoptotic rate of lung cancer cells induced by survivin ASODN was decreased significantly. No up-regrulation and activation in caspase-8 protein was observed.

CONCLUSION

Survivin inhibits apoptosis via regulation of mitochondrial-dependent pathway. survivin ASODN can not only induce apoptosis but also inhibit cell proliferation through blocking the expression of survivin mRNA and protein.

Suppression of early growth response factor-1 with egr-1 antisense oligodeoxynucleotide aggravates experimental duodenal ulcers

Previously, we demonstrated that cysteamine releases endothelin-1 in the rat duodenal mucosa, followed by increased expression of early growth response factor-1 (egr-1). We hypothesized that egr-1 is a key mediator gene in the multifactorial mechanisms of duodenal ulcer development and healing because its protein, transcription factor product Egr-1, regulates the expression of angiogenic growth factors. We wanted to determine the effect of egr-1 antisense oligonucleotide on cysteamine-induced duodenal ulcers as well as on the expression of bFGF, PDGF, and VEGF, of which synthesis is modulated by Egr-1. An antisense oligonucleotide to egr-1 was used to inhibit the synthesis of Egr-1 and to determine its effect on ulcer formation in the rat model of cysteamine-induced duodenal ulceration. Real-time RT-PCR and Western blot analysis were used to assess the expression of Egr-1 mRNA and protein as well as ERK, bFGF, PDGF, and VEGF. The antisense Egr-1 oligonucleotide inhibited the expression of egr-1 mRNA and protein and increased the duodenal ulcer size from 8.1 +/- 1.8 mm(2) in controls to 20.7 +/- 4.0 mm(2) (P < 0.01). Cysteamine induced phosphorylation of ERK1/2 and enhanced the synthesis of bFGF, PDGF, and VEGF in the preulcerogenic stages of duodenal ulceration, whereas egr-1 antisense oligonucleotide markedly decreased the expression of these growth factors in the duodenal mucosa. We also demonstrated that Egr-1 expression relates to the ulcerogenic effect of cysteamine because these actions were not exerted by the toxic analog ethanolamine. Thus Egr-1 seems to play a critical role in duodenal ulceration because Egr-1 downregulation aggravates experimental duodenal ulcers, most likely through the transcriptional inhibition of bFGF, PDGF, and VEGF synthesis.

[Inhibition of A549 cells by polybutylcyanoacrylate nanoparticles loaded with antisense oligodeoxynucleotide of hTERT mRNA]

AIM

To investigate the effect of nanoparticles for antisense oligodeoxynucleotide (ASODN) of hTERT mRNA on A549 cells.

METHODS

The cationic polybutylcyanoacrylate nanoparticles (NPs) were prepared by an emulsion polymerization process in the presence of DEAE-dextran. Antisense oligodeoxynucleotides were loaded on the particles by adsorption. The cytotoxicity of NPs and proliferation of A549 cells were detected by MTT assay. Intracellular fluorescence intensity after transfecting the 5'-FITC-labelled ASODN (FASODN) and cell cycles were determined by flow cytometry (FCM). Inverse microscope was used to observe the modality of A549 cell transfected by NPs for ASODN. The protein expression of hTERT was measured by immunocytochemistry.

RESULTS

The cytotoxicity increased evidently with the increasing concentration of NPs over 2.5 g x L(-1). The intracellular fluorescence in FASODN-NP group was obviously stronger than that in FASODN group (NPs free) after transfection for 24 h (P < 0.01). The inhibitory rate for cell modality change and proliferation after the treatment with ASODN-NP at 72 h reached peak , 62.4% , 44.6% and 36.4% for ASODN1-NP group, ASODN2-NP group and ASODN3-NP group, respectively; The cell cycle in ASODN-NP group varied observably compared with control group and sense oligodeoxynucleotide-nanoparticle (SODN-NP) group and the cell cycle was blocked in G1 phase, the cell number in S phase decreased obviously (P < 0.01); The hTERT protein expression of ASODN-NP group reduced clearly.

CONCLUSION

ASODN-NP of hTERT can inhibit the proliferation of A549 cells effectively and cause the change of cell cycle, restraint of protein expression of hTERT and cell viability.

Tumor necrosis factor-a antisense transfer remarkably improves hepatic graft viability

BACKGROUND

Cold ischemia/reperfusion injury of the hepatic graft, an unsolved problem in liver transplantations, is attributed to the release of inflammatory cytokines, especially the tumor necrosis factor- (TNF) alpha, from activated Kupffer cells (KC). Therefore, the specific inhibition of TNF-alpha could improve the viability of the hepatic graft upon reperfusion.

METHODS

We assessed the efficacy of TNF-alpha antisense (TNF-AS) oligodeoxynucleotides (ODNs) delivery to KC in a rodent liver transplantation model.

RESULTS

Seventy-one percent of the animals that received 6 hours preserved grafts in baths of lactated Ringer's solution (4 degrees C) and were treated with TNF-AS survived for over 14 days. Eighty percent of the animals treated with vehicle, sense ODNs, or balanced salt saline (BSS) died. Four hours after reperfusion of the liver, a significant reduction was noted in livers treated with TNF-AS in the release of cytosolic enzymes from the hepatocytes and the serum TNF-alpha (P<0.05). The expressions of TNF-alpha on KC and of intercellular adhesion molecule-1 on sinusoidal endothelial cells were completely suppressed in TNF-AS-treated livers.

CONCLUSIONS

TNF-AS delivery improves the viability of the hepatic graft, and this technique may solve hepatic graft nonfunction in a clinical setting.

Intravenous infusion of an antisense oligonucleotide results in exon skipping in muscle dystrophin mRNA of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease that is characterized by muscle dystrophin deficiency. We report that intravenous (IV) infusion of an antisense oligonucleotide created an in-frame dystrophin mRNA from an out-of-frame DMD mutation (via exon skipping) which led to muscle dystrophin expression. A 10-year-old DMD patient possessing an out-of-frame, exon 20 deletion of the dystrophin gene received a 0.5 mg/kg IV infusion of an antisense 31-mer phosphorothioate oligonucleotide against the splicing enhancer sequence of exon 19. This antisense construct was administered at one-week intervals for 4 wk. No side effects attributable to infusion were observed. Exon 19 skipping appeared in a portion of the dystrophin mRNA in peripheral lymphocytes after the infusion. In a muscle biopsy one week after the final infusion, the novel in-frame mRNA lacking both exons 19 and 20 was identified and found to represent approximately 6% of the total reverse transcription PCR product. Dystrophin was identified histochemically in the sarcolemma of muscle cells after oligonucleotide treatment. These findings demonstrate that phosphorothioate oligonucleotides may be administered safely to children with DMD, and that a simple IV infusion is an effective delivery mechanism for oligonucleotides that lead to exon skipping in DMD skeletal muscles.