Immunologic Heterogeneity in 2 Cartilage-Hair Hypoplasia Patients With a Distinct Clinical Course

BACKGROUND AND OBJECTIVE

Cartilage-hair hypoplasia (CHH) syndrome is a rare autosomal recessive syndrome associated with skeletal dysplasia, varying degrees of combined immunodeficiency (CID), short stature, hair hypoplasia, macrocytic anemia, increased risk of malignancies, and Hirschsprung disease. To provide clinical and immunological insights obtained from 2 unrelated patients who displayed clinical characteristics of CHH.

METHODS

Two patients with suspected CHH syndrome due to skeletal dysplasia and immunodeficiency underwent an immunological and genetic work-up using flow cytometry, next-generation sequencing (NGS) of the immune repertoire, and Sanger sequencing to identify the underlying defects.

RESULTS

Patient 1 presented with low birth weight and skeletal dysplasia. Newborn screening was suggestive of T-cell immunodeficiency, as T-cell receptor excision circle levels were undetectable. Both the T-cell receptor (TCR) Vß and TCR-g (TRG) repertoires were restricted, with evidence of clonal expansion. Genetic analysis identified compound heterozygous RMRP variants inherited from both parents. Patient 2 presented with recurrent lung and gastrointestinal infections, skeletal dysplasia, failure to thrive, and hepatomegaly. The polyclonal pattern of the TCRß repertoire was normal, with only slight overexpression of TCR-ßV20 and restricted expression of Vßs. TRG expressed a normal diverse repertoire, similar to that of the healthy control sample. Genetic analysis identified biallelic novel regulatory variants in RMRP. Both parents are carriers of this mutation.

CONCLUSION

Our findings demonstrate how the immunological work-up, supported by genetic findings, can dramatically change treatment and future outcome in patients with the same clinical syndrome.

AD-9308 ameliorates the impacts of 4-HNE on the progress of pulmonary arterial hypertension in aldehyde dehydrogenase 2*1*2 knock-in mice

 

Endothelial dysfunctions play a critical role on the development of pulmonary arterial hypertension (PAH). It has been reported that the one-year mortality rate is still up to 15% even with PAH-targeted therapy, implying that there may be untargeted pathways. 4-hydroxynenonal (4-HNE), an unsaturated aldehyde, is highly induced in the lungs of PAH animals and its serum levels were also reported to be higher in PAH patients. 4-HNE is metabolized by mitochondrial aldehyde dehydrogenase (ALDH2), which is dysfunctional in near 40% of East Asian people. Currently, the impacts of 4-HNE on endothelial dysfunctions in the development of PAH are unclear. In terms of translational medicine, we proposed that modulation of 4-HNE level may alleviate the progress of PAH patients with ALDH2 deficiency.

We found that 4-HNE alone was not sufficient to induce pulmonary artery endothelial cell (PAEC) functional changes, including proliferation, migration and tube formation, whereas their effects emerge from the depletion of ALDH2. We further mimicked human ALDH2 functional deficiency by using daidzin (DZN), an inhibitor which is able to block the substrate binding site of ALDH2. ALDH2 functional inhibition alone did not induce any PAEC functional change, while an add-on of 4-HNE impaired PAEC functions. In addition, 4-HNE significantly reduced eNOS activity with combined DZN treatment. Consistent with the mechanism of ALDH2 activity-mediated angiogensis, ALDH2 enhancers Alda-1 and AD-5591 completely reverse the anti-angiogenic effects of 4-HNE in the presence of DZN. To further confirm whether ALDH2 functional deficiency impact on PAH development in mammals, heterozygous ALDH2*1/*2 transgenic and wild-type mice were subjected to chronic hypoxia to induce PAH. ALDH2*1/*2 transgenic mice had similar right ventricular systolic pressure (RVSP) as wild-type mice. However, after exposure to chronic hypoxia, ALDH2*1/*2 transgenic mice indeed developed a significantly higher RVSP than that in wild-type mice. Furthermore, we demonstrated that 4-HNE expression was profoundly enhanced in ALDH2*1/*2 transgenic mice by chronic hypoxia-induced PAH with pulmonary artery smooth muscle cell hyperplasia. More importantly, we found that AD-9308, an enhancer of ALDH2 significantly decreased hypoxia-induced RVSP elevation in heterozygous ALDH2*1/*2 transgenic mice.

Taken together, our data demonstrate that 4-HNE and ALDH2 functional deficiency potentially contribute to PAH development and worsening, and that ALDH2 enhancers may be promising as a PAH adjunct therapy, particularly for patients with ALDH2 nonfunctional alleles.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology, Taiwan

The safety and clinical effectiveness of rapid infusion with CT-P10 in patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia: A retrospective non-interventional post-authorization safety study in Europe

Rapid infusion (RI) of the rituximab biosimilar CT-P10 is currently only an approved treatment regimen for the treatment of rheumatoid arthritis. Although both CT-P10 and reference rituximab are known to be frequently administered using a RI regimen (≤90 min) in clinical practice, published data on the safety of RI of CT-P10 in patients with NHL and CLL are limited. Hence, this study collected real-world safety and effectiveness data on RI-CT-P10 from the medical records of 196 patients with NHL or CLL in 10 European centers, 6 months after the date of the first RI (index date); the infusion-related reaction (IRR) rate was compared to previously published data. Ten percent (95% confidence interval 6%-15%; n = 20/196) of patients experienced an infusion-related reaction (IRR) on day 1-2 post-index, which was not significantly different (p = 0.45) to the IRR rate for rituximab described in a previous meta-analysis (8.8%). During the observation period, 2% of patients experienced grade 3-5 IRRs and 85% (n = 166) experienced an adverse event (non-IRR). The most common reason for discontinuation of first-line CT-P10 was planned treatment completion (81%; n = 158). Complete response and partial response to CT-P10 was observed in 74% (n = 142/192) and 22% (n = 42/192) of patients, respectively. The results of this real-world study demonstrate that the safety and effectiveness profile of RI-CT-P10 is similar to RI of reference rituximab and therefore support the current use of RI-CT-P10 in patients with NHL and CLL.

Altered T cell receptor beta repertoire patterns in pediatric ulcerative colitis

The antigenic specificity of T cells occurs via generation and rearrangement of different gene segments producing a functional T cell receptor (TCR). High-throughput sequencing (HTS) allows in-depth assessment of TCR repertoire patterns. There are limited data concerning whether TCR repertoires are altered in inflammatory bowel disease. We hypothesized that pediatric ulcerative colitis (UC) patients possess unique TCR repertoires, resulting from clonotypical expansions in the gut. Paired blood and rectal samples were collected from nine newly diagnosed treatment-naive pediatric UC patients and four healthy controls. DNA was isolated to determine the TCR-β repertoire by HTS. Significant clonal expansion was demonstrated in UC patients, with inverse correlation between clinical disease severity and repertoire diversity in the gut. Using different repertoire variables in rectal biopsies, a clear segregation was observed between patients with severe UC, those with mild-moderate disease and healthy controls. Moreover, the overlap between autologous blood-rectal samples in UC patients was significantly higher compared with overlap among controls. Finally, we identified several clonotypes that were shared in either all or the majority of UC patients in the colon. Clonal expansion of TCR-β-expressing T cells among UC patients correlates with disease severity and highlights their involvement in mediating intestinal inflammation.

Photovoltaic properties of novel thiophene- and selenophene-based conjugated low bandgap polymers: a comparative study

We investigated the photovoltaic properties of two newly synthesized low bandgap conjugated polymers, thiophene-based P1 and selenophene-based P2.

Macrophage cell death and transcriptional response are actively triggered by the fungal virulence factor Cbp1 during H. capsulatum infection

Microbial pathogens induce or inhibit death of host cells during infection, with significant consequences for virulence and disease progression. Death of an infected host cell can either facilitate release and dissemination of intracellular pathogens or promote pathogen clearance. Histoplasma capsulatum is an intracellular fungal pathogen that replicates robustly within macrophages and triggers macrophage lysis by unknown means. To identify H. capsulatum effectors of macrophage lysis, we performed a genetic screen and discovered three mutants that grew to wild-type levels within macrophages but failed to elicit host-cell death. Each mutant was defective in production of the previously identified secreted protein Cbp1 (calcium-binding protein 1), whose role in intracellular growth had not been fully investigated. We found that Cbp1 was dispensable for high levels of intracellular growth but required to elicit a unique transcriptional signature in macrophages, including genes whose induction was previously associated with endoplasmic reticulum stress and host-cell death. Additionally, Cbp1 was required for activation of cell-death caspases-3/7, and macrophage death during H. capsulatum infection was dependent on the pro-apoptotic proteins Bax and Bak. Taken together, these findings strongly suggest that the ability of Cbp1 to actively program host-cell death is an essential step in H. capsulatum pathogenesis.

Specificity protein 1 expression contributes to Bcl-w-induced aggressiveness in glioblastoma multiforme

We already had reported that Bcl-w promotes invasion or migration in gastric cancer cells and glioblastoma multiforme (GBM) by activating matrix metalloproteinase-2 (MMP-2) via specificity protein 1 (Sp1) or β-cateinin, respectively. High expression of Bcl-w also has been reported in GBM which is the most common malignant brain tumor and exhibits aggressive and invasive behavior. These reports propose that Bcl-w-induced signaling is strongly associated with aggressive characteristic of GBM. We demonstrated that Sp1 protein or mRNA expression is induced by Bcl-w using Western blotting or RT-PCR, respectively, and markedly elevated in high-grade glioma specimens compared with low-grade glioma tissues using tissue array. However, relationship between Bcl-w-related signaling and aggressive characteristic of GBM is poorly characterized. This study suggested that Bcl-w-induced Sp1 activation promoted expression of glioma stem-like cell markers, such as Musashi, Nanog, Oct4 and sox-2, as well as neurosphere formation and invasiveness, using western blotting, neurosphere formation assay, or invasion assay, culminating in their aggressive behavior. Therefore, Bcl-w-induced Sp1 activation is proposed as a putative marker for aggressiveness of GBM.

Synthesis and anticancer activity of di(3-thienyl)methanol and di(3-thienyl)methane

Di(3-thienyl)methanol (2) and di(3-thienyl)methane (3) have been synthesized and screened against the T98G (brain cancer) cell line. Treatment induced cell death (MTT and macro-colony assay), growth inhibition, cytogenetic damage (micronuclei formation), were studied as cellular response parameters. Treatment with the compounds enhanced growth inhibition and cell death in a concentration dependent manner in both T98G and HEK (normal) cell lines. At higher concentrations (>20 µg/mL) the cytotoxic effects of the compounds were highly significant. The effect on clonogenic capacity and micronuclei formation observed after treatment of cells. Amongst the compounds, compound 2 exhibited potent activity against T98G brain cancer cells. Despite potent in vitro activity, both compounds exhibited less cytotoxicity against normal human HEK cells at all effective concentrations.

Direct peroral cholangioscopy using an ultraslim upper endoscope for management of residual stones after mechanical lithotripsy for retained common bile duct stones

BACKGROUND AND STUDY AIMS

The incidence of residual stones after mechanical lithotripsy for retained common bile duct (CBD) stones is relatively high. Peroral cholangioscopy using a mother-baby system may be useful for confirming complete extraction of stones, but has several limitations regarding routine use. We evaluated the role of direct peroral cholangioscopy (DPOC) using an ultraslim upper endoscope for the evaluation and removal of residual CBD stones after mechanical lithotripsy.

PATIENTS AND METHODS

From August 2006 to November 2010, 48 patients who had undergone mechanical lithotripsy for retained CBD stones with no evidence of filling defects in balloon cholangiography were recruited. The bile duct was inspected by DPOC after balloon cholangiography. Detected residual CBD stones were directly retrieved with a basket or balloon catheter under DPOC. The incidence of residual stones detected by DPOC, and the success rate of residual stone retrieval under DPOC were investigated.

RESULTS

DPOC was successfully performed in 46 of the 48 patients (95.8%). Of these, 13 patients (28.3%) had residual CBD stones (mean number 1.4, range 1-3; mean diameter 4.5 mm, range 2.3-9.6). The residual stones were removed directly under DPOC in 11 of these patients (84.6%). There were no complications associated with DPOC or stone removal.

CONCLUSION

DPOC using an ultraslim upper endoscope is a useful endoscopic procedure for the evaluation and extraction of residual stones after mechanical lithotripsy for retained CBD stones.

Anti-influenza virus activity of green tea by-products in vitro and efficacy against influenza virus infection in chickens

Polyphenolic compounds present in green tea, particularly catechins, are known to have strong anti-influenza activity. The goal of this study was to determine whether green tea by-products could function as an alternative to common antivirals in animals compared to original green tea. Inhibition of viral cytopathic effects ascertained by neutral red dye uptake was examined with 50% effective (virus-inhibitory) concentrations (EC₅₀)determined. Against the H1N1 virus A/NWS/33, we found the anti-influenza activity of green tea by-products (EC₅₀ = 6.36 µg/mL) to be equivalent to that of original green tea (EC₅₀= 6.72 µg/mL). The anti-influenza activity of green tea by-products was further examined in mouse and chicken influenza infection models. In mice, oral administration of green tea by-products reduced viral titers in the lungs in the early phase of infection, but they could not protect these animals from disease and death. In contrast, therapeutic administration of green tea by-products via feed or water supplement resulted in a dose-dependent significant antiviral effect in chickens, with a dose of 10 g/kg of feed being the most effective (P < 0.001). We also demonstrated that unidentified hexane-soluble fractions of green tea by-products possessed strong anti-influenza activity, in addition to ethyl acetate-soluble fractions, including catechins. This study revealed green tea by-product extracts to be a promising novel antiviral resource for animals.

Misexpression screen delineates novel genes controlling Drosophila lifespan

In an initial preliminary screen we identified factors associated with controlling Drosophila aging by examining longevity in adults where EP elements induced over-expression or antisense-RNA at genes adjacent to each insertion. Here, we study 45 EP lines that initially showed at least 10% longer mean lifespan than controls. These 45 lines and a daughterless (da)-Gal4 stock were isogenized into a CS10 wild-type background. Sixteen EP lines corresponding to 15 genes significantly extended lifespan when their target genes were driven by da-Gal4. In each case, the target genes were seen to be over-expressed. Independently derived UAS-gene transgenic stocks were available or made for two candidates: ImpL2 which is ecdysone-inducible gene L2, and CG33138, 1,4-alpha-glucan branching enzyme. With both, adult lifespan was increased upon over-expression via the GeneSwitch inducible Gal4 driver system. Several genes in this set of 15 correspond to previously discovered longevity assurance systems such as insulin/IGF-1 signaling, gene silencing, and autophagy; others suggest new potential mechanisms for the control of aging including mRNA synthesis and maturation, intracellular vesicle trafficking, and neuroendocrine regulation.

Characterization of Bacillus phage-K2 isolated from chungkookjang, a fermented soybean foodstuff

An investigation of a virulent Bacillus phage-K2 (named Bp-K2) isolated from chungkookjang (a fermented soybean foodstuff) was made. Bp-K2 differed in infectivity against a number of Bacillus subtilis strains including starter strains of chungkookjang and natto, being more infectious to Bacillus strains isolated from the chungkookjang, but much less active against a natto strain. Bp-K2 is a small DNA phage whose genome size is about 21 kb. Bp-K2 is a tailed bacteriophage with an isometric icosahedral head (50 nm long on the lateral side, 80 nm wide), a long contractile sheath (85-90 nm × 28 nm), a thin tail fiber (80-85 nm long, 10 nm wide), and a basal plate (29 nm long, 47 nm wide) with a number of spikes, but no collar. The details of the structures of Bp-K2 differ from natto phage ϕBN100 as well as other known Bacillus phages such as SPO1-like or ϕ 29-like viruses. These data suggest that Bp-K2 would be a new member of the Myoviridae family of Bacillus bacteriophages.

Activation of Macrophages by Exopolysaccharide Produced by MK1 Bacterial Strain Isolated from Neungee Mushroom, Sarcodon aspratus

Background

The MK1 strain, a novel bacterial isolate from soft-rotten tissue of the Neungee mushroom, produces copious amounts of exopolysaccharide (EPS) in a dextrose minimal medium. This study examined the molecular characteristics and immunomodulatory activity of MK1 EPS.

Methods

The EPS in the culture supernatant was purified by cold ethanol precipitation, and characterized by SDS-PAGE/silver staining and Bio-HPLC. The immunomodulatory activities of the EPS were examined using the mouse monocytic cell line, RAW 264.7 cells.

Results

The molecular weights of the purified EPS were rather heterogeneous, ranging from 10.6 to 55 kDa. The EPS was composed of glucose, rhamnose, mannose, galactose, and glucosamine at an approximate molar ratio of 1.00:0.8:0.71:0.29:0.21. EPS activated the RAW cells to produce cytokines, such as TNF-α and IL-1β, and nitric oxide (NO). EPS also induced the expression of co-stimulatory molecules, such as B7-1, B7-2 and ICAM-1, and increased the phagocytic activity. The macrophage-activating activity of EPS was not due to endotoxin contamination because the treatment of EPS with polymyin B did not reduce the macrophage-activating activity.

Conclusion

The EPS produced from the MK1 strain exerts macrophage-activating activity.

Integration target site selection by a resurrected human endogenous retrovirus

At least 8% of the human genome was formed by integration of retroviral DNA sequences. Here we analyze the forces directing the accumulation of human endogenous retroviruses (HERVs) by comparing de novo HERV integration targeting with the distribution of fixed HERV elements in the human genome. All known genomic HERVs are inactive due to mutation, but we were able to study integration targeting using a reconstituted consensus HERV-K (designated HERV-K(Con)). We found that HERV-K(Con) integrated preferentially in transcription units, in gene-rich regions, and near features associated with active transcription units and associated regulatory regions. In contrast, genomic HERV-K proviruses are found preferentially outside transcription units. The minority of genomic HERVKs present inside transcription units are in opposite transcriptional orientation relative to the host gene, the orientation predicted to be minimally disruptive to host mRNA synthesis, but de novo HERV-K(Con) integration within transcription units showed no orientation bias. We also found that the youngest HERV-K elements in the human genome showed a distribution intermediate between de novo HERV-K(Con) integration sites and older fixed HERV-Ks. These findings indicate that accumulation of HERVs in the human germline is a two-step process: integration targeting biases direct initial accumulation, then purifying selection leads to loss of proviruses disrupting gene function.

Effect of Chitosan Acetate on Bacteria Occurring on Neungee Mushrooms, Sarcodon aspratus

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom's appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were 3 × 10(-4) and 1.4 × 10(-3) after 24 h, and 2 × 10(-4) and 7 × 10(-4) after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were 1 × 10(-2) and 6.9 × 10(-3), respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for 2~3 second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

Pathogen virulence factors as molecular probes of basic plant cellular functions

To successfully colonize plants, pathogens have evolved a myriad of virulence factors that allow them to manipulate host cellular pathways in order to gain entry into, multiply and move within, and eventually exit the host for a new infection cycle. In the past few years, substantial progress has been made in characterizing the host targets of viral and bacterial virulence factors, providing unique insights into basic plant cellular processes such as gene silencing, vesicle trafficking, hormone signaling, and innate immunity. Identification of the host targets of additional pathogen virulence factors promises to continue shedding light on fundamental cellular mechanisms in plants, thus enhancing our understanding of plant signaling, metabolism, and cell biology.

Isoforms of glucose 6-phosphate dehydrogenase in Deinococcus radiophilus

Glucose 6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) in Deinococcus radiophilus, an extraordinarily UV-resistant bacterium, was investigated to gain insight into its resistance as it was shown to be involved in a scavenging system of superoxide (O2-1) and peroxide (O2-2) generated by UV and oxidative stresses. D. radiophilus possesses two G6PDH isoforms: G6PDH-1 and G6PDH-2, both showing dual coenzyme specificity for NAD and NADP. Both enzymes were detected throughout the growth phase; however, the substantial increase in G6PDH-1 observed at stationary phase or as the results of external oxidative stress indicates that this enzyme is inducible under stressful environmental conditions. The G6PDH-1 and G6PDH-2 were purified 122- and 44-fold (using NADP as cofactor), respectively. The purified G6PDH-1 and G6PDH-2 had the specific activity of 2,890 and 1,033 U/mg protein (using NADP as cofactor) and 3,078 and 1,076 U/mg protein (using NAD as cofactor), respectively. The isoforms also evidenced distinct structures; G6PDH-1 was a tetramer of 35 kDa subunits, whereas G6PDH-2 was a dimer of 60 kDa subunits. The pIs of G6PDH-1 and G6PDH-2 were 6.4 and 5.7, respectively. Both G6PDH-1 and G6PDH-2 were inhibited by both ATP and oleic acid, but G6PDH-1 was found to be more susceptible to oleic acid than G6PDH-2. The profound inhibition of both enzymes by beta-naphthoquinone-4-sulfonic acid suggests the involvement of lysine at their active sites. Cu2+ was a potent inhibitor to G6PDH-2, but a lesser degree to G6PDH-1. Both G6PDH-1 and G6PDH-2 showed an optimum activity at pH 8.0 and 30 degrees .

Reconstitution of an infectious human endogenous retrovirus

The human genome represents a fossil record of ancient retroviruses that once replicated in the ancestors of contemporary humans. Indeed, approximately 8% of human DNA is composed of sequences that are recognizably retroviral. Despite occasional reports associating human endogenous retrovirus (HERV) expression with human disease, almost all HERV genomes contain obviously inactivating mutations, and none are thought to be capable of replication. Nonetheless, one family of HERVs, namely HERV-K(HML-2), may have replicated in human ancestors less than 1 million years ago. By deriving a consensus sequence, we reconstructed a proviral clone (HERV-K_CON) that likely resembles the progenitor of HERV-K(HML-2) variants that entered the human genome within the last few million years. We show that HERV-K_CON Gag and protease proteins mediate efficient assembly and processing into retrovirus-like particles. Moreover, reporter genes inserted into the HERV-K_CON genome and packaged into HERV-K particles are capable of infectious transfer and stable integration in a manner that requires reverse transcription. Additionally, we show that HERV-K_CON Env is capable of pseudotyping HIV-1 particles and mediating entry into human and nonhuman cell lines. Furthermore, we show that HERV-K_CON is resistant to inhibition by the human retrovirus restriction factors tripartite motif 5α and apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) 3G but is inhibited by APOBEC 3F. Overall, the resurrection of this extinct infectious agent in a functional form from molecular fossils should enable studies of the molecular virology and pathogenic potential of this ancient human retrovirus.

Retrovirus genomes integrate into the genomes of host cells. If the target cells of a particular retrovirus include germ-line cells, e.g., sperm or egg cells, then retroviral genomes can be inherited like cellular genes. So-called “endogenous” retroviruses have accumulated throughout evolution in the genomes of many organisms, including humans. While all known endogenous retroviruses of modern humans are unable to replicate as retroviruses, the human genome represents a fossil record of ancient retroviruses that once infected our ancestors. In this study, a collection of “dead” endogenous retroviral genomes in modern human DNA was used to deduce the approximate sequence of an ancestral retrovirus, human endogenous retrovirus (HERV)-K, that is now thought to be extinct. A pseudo-ancestral HERV-K DNA sequence was synthesized and used to produce viral proteins and RNA that could reconstitute the HERV-K replication cycle. Thus, the replication and biology of a once-extinct retrovirus can now be studied in the laboratory. Interestingly, reconstituted HERV-K replication experiments, and comparison of the reconstituted HERV-K DNA sequence with the dead HERV-Ks in modern human DNA, suggests that HERV-K may have been extinguished in humans in part by host defenses that induce mutation of retroviral DNA and that the reconstitution of the pseudo-ancestral HERV-K reversed these changes.

Identification of bacteria isolated from diseased Neungee mushroom,Sarcodon aspratus

As the first step in an investigation of the problem with quality deterioration seen in the Neungee mushroom (Sarcodon aspratus) due to bacterial overgrowth during its storage, an attempt to isolate bacterial strains was made using infected gills of Sarcodon aspratus. Five bacterial strains were isolated; one phototrophic cyanobacterial species and four heterotrophic Gram negative rods. The four heterotrophic bacterial isolates (strains P, S, R, and MK1) were subjected to identification based on biochemical characteristics using the Biolog system, cellular fatty acid analysis using the MIDI system, cytology by scanning microscopy, and 16s rDNA sequence analysis. A slow grower, the P strain (ca. 0.7 microm x 1.5 microm), which forms pink colonies on Tryptic Soy agar (TSA) and glucose minimal salt medium containing thiamine (MT medium), belongs to genus Methylobacterium, and is likely M. radiotolerans. The methanol-utilizing capacity of the P strain was confirmed by growth on methanol-supplemented medium as a sole carbon source. Both the S and R strains (ca. 0.5 microm x 0.8 microm) produced smooth and slightly rough white colonies, respectively, on TSA, MT, and potato dextrose (PD) agar are members of the Burkholderia cepacia complex. Although both strains showed some differences from each other in colony morphology, nitrogen fixation capacity, and denitrification, they were considered to be Burkholderia stabilis because their 16s rDNA sequences showed 99.93% similarity with those of B. stabilis LMG 14294T (NCBI AF 148554). The MK1 strain, a rod-shaped bacterium with a tapered end (ca. 0.6 microm x 1.8 microm), produces a copious mucoid substance on MT and PD agar, but not on TSA. Despite extensive identification studies, the M strain is not currently identifiable, which suggests that it is a novel bacterium.

Occurrence of thioredoxin reductase in Deinococcus species, the UV resistant bacteria

The occurrence of thioredoxin reductase (NAD(P)H: oxidized-thioredoxin reductase, EC 1.6.4.5, TrxR) in five mesophilic species of Deinococcus was investigated by PAGE. Each species possessed a unique TrxR pattern, for example, a single TrxR characterized D. radiopugnans while multiple forms of TrxR occurred in other Deinococcal spp. Most of TrxRs occurring in Deinococcus showed dual cofactor specificity, active with either NADH or NADPH, although the NADPH specific-TrxR was observed in D. radiophilus and D.proteolyticus.

Hepatocellular carcinoma model cell lines with two distinct migration modes

Migration is an essential feature of metastatic cancer cells. To understand how motility is regulated in hepatocellular carcinoma, we analyzed gene expression profiles of mouse model cell lines we established from transgenic mice carrying SV40 large T antigen. A non-motile HC9 cell line was isolated from mouse liver tumors, and two additional cell lines, HCM1 and HCM4, were derived from HC9 cells. We found that both HCM1 and HCM4 cells were substantially more migratory than HC9, and that HCM1 generated tumor nodules in nude mice. In contrast to HCM4 cells that exhibited mesenchymal cell-type gene expression similar to HC9 cells, HCM1 cells appeared to have undergone a mesenchymal-amoeboidal transition. Thus, HCM1 and HCM4 cells have distinct migration and gene expression patterns, and together with HC9 cells, they can serve as model cell lines for understanding how migration is acquired and controlled in hepatocellular carcinoma.

Functional characterization of mutant CYP17 genes isolated from a 17 alpha-hydroxylase/17,20-lyase-deficient patient

CYP17 has a dual enzymatic activity that is necessary for steroid hormone biosynthesis. It catalyzes the 17 alpha-hydroxylation of progesterone or pregnenolone and also removes an acetyl moiety of hydroxy-progesterone or hydroxypregnenolone by its 17,20-lyase activity to produce androstenedione or dehydroepiandrosterone (DHEA), respectively. We previously isolated a compound heterozygous mutant of CYP17 from a Korean female patient: 1-base deletion and 1-base transversion mutation at 1 allele and 3-base deletion mutation at the other allele. Here we tested the functional activities of these 2 mutant CYP17 alleles using a transfection analysis in COS-1 cells with radiolabeled substrates and thin layer chromatography. Both mutant CYP17 genes lost not only 17 alpha-hydroxylation activity, but also 17,20-lyase activity in this assay system. This nonfunctional nature of 2 mutant CYP17 genes explains the clinical manifestation of a patient who had 17 alpha-hydroxylase deficiency.

Purification and some properties of superoxide dismutase from Deinococcus radiophilus, the UV-resistant bacterium

The superoxide dismutase (SOD, EC 1.15.1.1) of Deinococcus radiophilus, a bacterium extraordinarily resistant to UV, ionizing radiations, and oxidative stress, was purified 1,920-fold with a 58% recovery yield from the cell-free extract of stationary cells by steps of ammonium sulfate fractionation and Superdex G-75 gel-filtration chromatography. A specific activity of the purified enzyme preparation was ca. 31,300 U mg(-1) protein. D. radiophilus SOD is Mn/FeSOD, judging by metal analysis and its insensitivity to cyanide and a partial sensitivity to H2O2. The molecular weights of the purified enzyme estimated by gel chromatography and polyacrylamide gel electrophoresis are 51.5+/-1 and 47.1+/-5 kDa, respectively. The SOD seems to be a homodimeric protein with a molecular mass of 26 +/- 0.5 kDa per monomer. The purified native SOD showed very acidic pI of ca. 3.8. The enzyme was stable at pH 5.0-11.0, but quite unstable below pH 5.0. SOD was thermostable up to 40 degrees C, but a linear reduction in activity above 50 degrees C. Inhibition of the purified SOD activity by beta-naphthoquinone-4-sulfonic acid, rho-diazobenzene sulfonic acid, and iodine suggests that lysine, histidine, and tyrosine residues are important for the enzyme activity. The N-terminal peptide sequence of D. radiophilus Mn/FeSOD (MAFELPQLPYAYDALEPHIDA(> D) is strikingly similar to those of D. radiodurans MnSOD and Aerobacter aerogenes FeSOD.

Production of superoxide dismutase by Deinococcus radiophilus

The production of superoxide dismutase (SOD) varied in Deinococcus radiophilus, the UV resistant bacterium, depending upon different phases of growth, UV irradiation, and superoxide treatment. A gradual increase in total SOD activity occurred up to the stationary phases. The electrophoretic resolution of the SOD in cell extracts of D. radiophilus at each growth phase revealed the occurrence of MnSOD throughout the growth phases. The SOD profiles of D. radiophilus at the exponential phase received oxidative stress by the potassium superoxide treatment or UV irradiation also revealed the occurrence of a single SOD. However, these treatments caused an increase in SOD activity. The data strongly suggest that D. radiophilus has only one species of SOD as a constitutive enzyme, which seems to be a membrane-associated protein.

Short-term temporal variation in PM2.5 mass and chemical composition during the Atlanta Supersite Experiment, 1999

Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supersite Experiment in August 1999. These independent instruments for aerosol chemical speciation of NO3-, SO4(2-), NH4+, and organic and elemental carbon (OC and EC), reconstructed the observed hourly dry PM2.5 mass to within 20% or better. Data from the experiment indicated that transient PM2.5 events were ubiquitous in Atlanta and were typically characterized by a sudden increase of EC (soot) and OC in the early morning or SO4(2-) in the late afternoon. The frequent temporal decoupling of these events provides insights into their origins, suggesting mobile sources in metro Atlanta as the main contributor to early morning PM2.5 and more regionally located point SO2 sources for afternoon PM2.5 events. The transient events may also have health implications. New data suggest that short-term PM2.5 exposures may lead to adverse health effects. Standard integrated filter-based techniques used in PM2.5 compliance monitoring networks and in most past PM2.5 epidemiologic studies collect samples over 24-hr periods and thus are unable to capture these transient events. Moreover, health-effects studies that focus on daily PM2.5 mass alone cannot evaluate the health implications of the unique and variable chemical properties of these episodes.

Heterogeneity of myocardial sleeve morphology and gap junctions in canine superior vena cava

BACKGROUND

The myocardial sleeve of the superior vena cava (SVC) has been identified as a potential initiating focus in atrial fibrillation, but information on cell-to-cell linkage at this site is lacking.

METHODS AND RESULTS

We examined the SVC in 8 dogs by immunoconfocal and electron microscopy. Cardiomyocytes outlined with vinculin and bearing striations positive for alpha-actinin are found in the proximal segment of the SVC. These cells, grouped in bundles of various orientations according to location, extend cephalically as far as 3 cm from the right atrium (RA)-SVC junction. Comparison between the junctional level and the level 2 cm distal shows that the myocardial layer in the latter is thinner and not as compact and is composed of longer cells (87.3+/-15.7 versus 71.6+/-14.4 micrometer, P<0.01). Gap junctions made of connexin43 (Cx43), Cx40, and Cx45 are aggregated mainly at the intercalated disks, and colocalization of connexins is a common feature throughout the myocardial sleeve. Areas of atypical expression exist, however, characterized by a center of abundant Cx43 labels surrounded by a periphery of scattered tiny Cx40-labeled spots. Although in the ventral subluminal compact myocardial layer, individual cells at both levels are surrounded by similar numbers of cells, the number of aggregation of labeled gap junctions at the distal level is less (2.3+/-0.6 versus 3.7+/-0.9, P<0.01). In addition, electron-microscopic examination demonstrates that the gap junctions at the distal level are smaller in size (0.37+/-0.30 versus 0.55+/-0.34 micrometer, P<0.01).

CONCLUSIONS

The myocardial sleeve in the canine SVC is a heterogeneous structure, which could potentially form a substrate for heterogeneity of electrical coupling.

Identification of a role for the sialomucin CD164 in myogenic differentiation by signal sequence trapping in yeast

Determination and differentiation of skeletal muscle precursors requires cell-cell contact, but the full range of cell surface proteins that mediate this requirement and the mechanisms by which they work are not known. To identify participants in cell contact-mediated regulation of myogenesis, genes that encode secreted proteins specifically upregulated during differentiation of C2C12 myoblasts were identified by the yeast signal sequence trap method (K. A. Jacobs, L. A. Collins-Racie, M. Colbert, M. Duckett, M. Golden-Fleet, K. Kelleher, R. Kriz, E. R. La Vallie, D. Merberg, V. Spaulding, J. Stover, M. J. Williamson, and J. M. McCoy, Gene 198:289-296, 1997), followed by RNA expression analysis. We report here the identification of CD164 as a gene expressed in proliferating C2C12 cells that is upregulated during differentiation. CD164 encodes a widely expressed cell surface sialomucin that has been implicated in regulation of cell proliferation and adhesion during hematopoiesis. Stable overexpression of CD164 in C2C12 and F3 myoblasts enhanced their differentiation, as assessed by both morphological and biochemical criteria. Furthermore, expression of antisense CD164 or soluble extracellular regions of CD164 inhibited myogenic differentiation. Treatment of C2C12 cells with sialidase or O-sialoglycoprotease, two enzymes previously reported to destroy functional epitopes on CD164, also inhibited differentiation. These data indicate that (i) CD164 may play a rate-limiting role in differentiation of cultured myoblasts, (ii) sialomucins represent a class of potential effectors of cell contact-mediated regulation of myogenesis, and (iii) carbohydrate-based cell recognition may play a role in mediating this phenomenon.

Structure-activity relationship studies of isoquinolinone type anticancer agent

Substituted isoquinolin-1-ones (1) were synthesized to test their in vitro anticancer activity. 3-Biphenyl-N-methylisoquinolin-1-one (7) showed the most potent anticancer activity against five different human cancer cell lines.

Mode of antiviral activity of water soluble components isolated from Elfvingia applanata on vesicular stomatitis virus

A preparation of water soluble components (EA) was made from carpophores of Elfvingia applanata (Pers.) Karst and its in vitro antiviral activity on vesicular stomatitis virus [(Indiana serotype, VSV(IND)] was investigated by plaque reduction assay. EA exhibited potent antiviral activity on VSV(IND) growth and negligible cytotoxicity on Vero cells, 50% effective concentration (EC50) of 104 microg/ml and 50% cytotoxic concentration (CC50) of 3,793 microg/ml, respectively. Selectivity index (SI, CC50/EC50) of EA on Vero cell and VSV(IND) was about 36.5. EA did not display either a direct virucidal effect on VSV(IND) or induction of antiviral substance by Vero cells upon its treatment. Thus, the mode of antiviral activity of EA was studied at steps of viral adsorption onto cell. When both EA and virus were added to cell monolayers, titer of cell-free virus in culture supernatant increased in ca. 30-40% compared with that of control group and titer of cell-associated virus was 60-100% higher than that of control group. These results suggested that antiviral activity of EA on VSV(IND) might be due to the hindrance of viral entry to cells at either endocytosis or loss of envelope.

Virtual reality for relearning daily living skills

The explosive increase in the power of computers has enabled the creation of fast, interactive 3D environments, sometimes called virtual reality (VR). This technology, often associated with arcade games, is increasingly being used for more serious applications. This paper describes research showing transfer of skills from a virtual environment to the real world. We then describe our VR authoring tool and an application to help cognitively impaired individuals relearn important daily living skills. Additionally we describe the development of a prototype networked system to enable a doctor to monitor remotely the rehabilitation of a group of patients.

Biochemical characterization of extracellular cAMP-dependent protein kinase as a tumor marker

In a recent report (Cho et al., Proc. Natl. Acad. Sci. USA 97, 835-840, 2000), we showed that cancer cells of various cell types secrete cAMP-dependent protein kinase (PKA) into the conditioned medium and that in the serum of cancer patients this extracellular PKA (ECPKA) is upregulated 10-fold as compared with normal serum. Here, we characterized the enzymatic properties of ECPKA that is present in the conditioned medium of PC3M prostate cancer cells and in the serum of cancer patients, and we compared ECPKA with PKA found in the cell extracts of PC3M cells. ECPKA present in the conditioned medium and human serum was not activated by cAMP addition, but intracellular PKA activity was totally dependent on the addition of cAMP. This indicates that the ECPKA is present in active, free C subunit form, whereas intracellular PKA is present in inactive holoenzyme form. ECPKA activity increased in a substrate concentration- and time-dependent manner, as did intracellular PKA. Both ECPKA and intracellular PKA activities were specifically inhibited by the PKA inhibitor protein, PKI. However, ECPKA activity was more temperature-sensitive than intracellular PKA; after two cycles of freezing/thawing, only 20% of initial ECPKA activity was detected compared with over 40% of intracellular PKA activity. Western blot analysis revealed the presence of a 40 kDa C(alpha) subunit of PKA in both conditioned medium and in the serum of cancer patients. These results suggest that ECPKA, out of the context of cAMP regulation, may function as a growth factor promoting cell growth and transformation; thus, it may serve as a tumor biomarker.

Age-related alteration of gap junction distribution and connexin expression in rat aortic endothelium

We investigated endothelial gap junctions and their three component connexins, connexin37 (Cx37), Cx40, and Cx43, during growth and senescence in rat aorta by en face immunoconfocal microscopy and electron microscopy. Gap junction spots labeled by specific antisera against Cx37, Cx40, and Cx43 were quantified at 1 day, 7 days, 28 days, 16 months, and > or =20 months of age, and the relationship between the connexins was examined by co-localization analysis. At birth, all three connexins were abundantly expressed; the number and total area of connexin spots then declined within 1 week (p<0.05 for each connexin). From 1 week, each connexin showed a distinct temporal expression pattern. Whereas Cx43 signal decreased progressively, Cx37 signal fluctuated in a downward trend. By contrast, Cx40 maintained an abundant level until > or =20 months of age (> or =20 months vs. 28 days, p<0.05 for number and total connexin signal area). These patterns were associated with changes in endothelial cell morphology. Double-label analysis showed that the extent of co-localization of connexins to the same gap junctional spot was age-dependent [>70% at birth and 28 days old; <70% at later stages (p<0.05)]. We conclude that expression of the three connexins in aortic endothelium is age-related, implying specific intercellular communication requirements during different stages after birth.

Compensatory stabilization of RIIbeta protein, cell cycle deregulation, and growth arrest in colon and prostate carcinoma cells by antisense-directed down-regulation of protein kinase A RIalpha protein

The cyclic AMP-dependent protein kinase (PKA) exists in two isoforms, PKA-I (type I) and PKA-II (type II), that contain an identical catalytic (C) subunit but distinct regulatory (R) subunits, RI and RII, respectively. Increased expression of RIalpha/PKA-I has been shown in human cancer cell lines, in primary tumors, in cells after transformation, and in cells upon stimulation of growth. We have shown previously that a single-injection RI, antisense treatment results in a reduction in RIalpha and PKA-I expression and sustained inhibition of human colon carcinoma growth in athymic mice (M. Nesterova and Y. S. Cho-Chung, Nat. Med., 1: 528-533, 1995). Growth inhibition accompanied reduction in RIalpha/PKA-I expression and compensatory increases in RIIbeta protein and PKA-IIbeta, the RIIbeta-containing holoenzyme. Here, we report that these in vivo findings are consistent with observations made in cancer cells in culture. We demonstrate that the antisense depletion of RIalpha in cancer cells results in increased RIIbeta protein without increasing the rate of RIIbeta synthesis or RIIbeta mRNA levels. Pulse-chase experiments revealed a 3-6-fold increase in the half-life of RIIbeta protein in antisense-treated colon and prostate carcinoma cells with little or no change in the half-lives of RIalpha, RIIalpha, and Calpha proteins. Compensation by RIIbeta stabilization may represent a novel biochemical adaptation mechanism of the cell in response to sequence-specific loss of RIalpha expression, which leads to sustained down-regulation of PKA-I activity and inhibition of tumor growth.

CRE-decoy oligonucleotide-inhibition of gene expression and tumor growth

Nucleic acid molecules with high affinities for a target transcription factor can be introduced into cells as decoy cis-elements to bind these factors and alter gene expression. This review discusses a synthetic single-stranded palindromic oligonucleotide, which self-hybridizes to form a duplex/hairpin and competes with cAMP response element (CRE) enhancers for binding transcription factors. This oligonucleotide inhibits CRE- and Ap-1-directed gene transcription and promotes growth inhibition in vitro and in vivo in a broad spectrum of cancer cells, without adversely affecting normal cell growth. Evidence presented here suggests that the CRE-decoy oligonucleotide can provide a powerful new means of combating cancers, viral diseases, and other pathological conditions by regulating the expression of cAMP-responsive genes.

CRE-transcription factor decoy oligonucleotide inhibition of MCF-7 breast cancer cells: cross-talk with p53 signaling pathway

The CRE, 5'-TGACGTCA-3', has been described as the consensus sequence for the cis-element that directs cAMP-regulated gene expression. Many transcription factors bind to this element and regulate the expression of a wide variety of cellular and viral genes. We have shown that CRE-transcription factor decoy oligonucleotide restrains the growth of cancer cells in vitro and in vivo [Park, Y. G., Nesterova, M., Agrawal, S., and Cho-Chung, Y. S. (1999) J. Biol. Chem. 274, 1573-1580]. The growth inhibition was accompanied by changes in cell morphology and apoptosis. To elucidate the molecular mechanism(s) of the growth inhibition by the CRE-decoy oligonucleotide, we investigated the p53 signaling pathway. Herein, we report that CRE-decoy oligonucleotide treatment results in an increase in the p53 protein level in MCF-7 human breast cancer cells that express wild-type p53. The p21WAF1/Cip1 protein levels were also increased in the CRE-decoy oligonucleotide treated cells accompanying a reduction in Cdk2- and cyclin E-dependent kinase activity and pRb phosphorylation. Pulse-chase experiments reveal that the p53 upregulation was due to increased stability of the protein. The decoy oligonucleotide treatment also enhanced the p53 promotor-directed transcription in vivo along with the increase in p53-CBP (CREB-binding protein) complex formation. Thus, the stabilization and activation of p53 may have contributed to the growth inhibition induced by CRE-transcription factor decoy oligonucleotide in MCF-7 breast cancer cells. This decoy oligonucleotide approach offers great promise as a tool for defining cellular regulatory processes and treating cancer and other diseases.

Production of two different catalase-peroxidases by Deinococcus radiophilus

The production of two kinds of catalase-peroxidase, viz. catalase-2 and catalase-3 of Deinococcus radiophilus varied depending upon growth phases and oxidative stress. A gradual increase in total catalase activity occurred during exponential and stationary phase. Electrophoretic resolution of these catalases in Deinococcal cell extracts revealed the uniform occurrence of catalase-2 and the appearance of catalase-3 only during the late exponential and stationary phase. A substantial increase in total catalase was observed in either hydrogen peroxide- or UV-treated cells. Monitoring of D. radiophilus catalase activity in the oxidative stressed and non-treated cells by gel electrophoresis followed by densitometry revealed the several-fold increase in catalase-3, which is above the constant level of catalase-2. The occurrence of catalase-3 and catalase-2 revealed by fractionation of sucrose-shocked cells suggests that catalase-3 is a cytosolic inducible enzyme whereas catalase-2 is the membrane-associated constitutive enzyme.

Extracellular protein kinase A as a cancer biomarker: its expression by tumor cells and reversal by a myristate-lacking Calpha and RIIbeta subunit overexpression

Overexpression of cAMP-dependent protein kinase (PKA) type I isozyme is associated with cell proliferation and neoplastic transformation. The presence of PKA on the external surface of LS-174T human colon carcinoma cells has been shown. Here, we show that cancer cells of various cell types excrete PKA into the conditioned medium. This extracellular PKA (ECPKA) is present in active, free catalytic subunit (C subunit) form, and its activity is specifically inhibited by PKA inhibitory protein, PKI. Overexpression of the Calpha or RIalpha subunit gene of PKA in an expression vector, which up-regulates intracellular PKA type I, markedly up-regulates ECPKA expression. In contrast, overexpression of the RIIbeta subunit, which eliminates PKA type I, up-regulates PKA type II, and reverts the transformed phenotype, down-regulates ECPKA. A mutation in the Calpha gene that prevents myristylation allows the intracellular PKA up-regulation but blocks the ECPKA increase, suggesting that the NH(2)-terminal myristyl group of Calpha is required for the ECPKA expression. In serum of cancer patients, the ECPKA expression is up-regulated 10-fold as compared with normal serum. These results indicate that the ECPKA expression is an ordered cellular response of a living cell to actively exclude excess intracellular PKA molecules from the cell. This phenomenon is up-regulated in tumor cells and has an inverse relationship with the hormone dependency of breast cancer. Thus, the extracellular PKA may serve as a potential diagnostic and prognostic marker for cancer.

Antisense DNA-targeting protein kinase A-RIA subunit: a novel approach to cancer treatment

Enhanced expression of the RIa subunit of cAMP-dependent protein kinase type I (PKA-I) has been shown during carcinogenesis, in human cancer cell lines and in primary tumors. We demonstrate that the sequence-specific inhibition of RIa gene expression by antisense oligonucleotides results in the differentiation of leukemia cells and growth arrest of cancer cells of epithelial origin and tumors in mice. The loss of RI by the antisense results in rapid increase in the half-life of the competitor molecule, RII protein, via its stabilization in a holoenzyme complex (PKA-II) that insures depletion of PKA-I and sustained inhibition of tumor growth. RI antisense, which restrains tumor cell growth by turning on the signals for blockade of tumor cell survival, namely blockade of the tyrosine kinase signaling, cell cycle deregulation and apoptosis, provides a single gene-targeting approach to treatment of cancer.

Suppression of microphthalmia transcriptional activity by its association with protein kinase C-interacting protein 1 in mast cells

Microphthalmia (mi) is a transcription factor that plays a major role in the regulation of growth and function in mast cells and melanocytes. Association of mi with other proteins is a critical step in the regulation of mi-mediated transcriptional activation. We found protein kinase C-interacting protein 1 (PKCI) specifically associated with mi in yeast two-hybrid screening. Immunoprecipitation of mi from quiescent rat basophilic leukemic cells or mouse melanocytes resulted in the specific co-immunoprecipitation of PKCI. This association was significantly reduced on engagement of the surface FcepsilonRI of mast cells or engagement of the Kit receptor on melanocytes. Hence, cell activation caused disengagement of mi from PKCI. Microphthalmia was previously shown to activate the mouse mast cell protease 6 (mMCP-6) promoter. Cotransfection of mi with PKCI in NIH 3T3 fibroblasts containing an mMCP-6 promoter-luciferase reporter demonstrated an up to 94% inhibition of mi-mediated transcriptional activation. PKCI by itself, although localized in the cytosol and nucleus of the cells, has no known physiological function and did not demonstrate transcriptional activity. Its ability to suppres mi transcriptional activity in the transient transfected fibroblast system suggests that it can function in vivo as a negative regulator of mi-induced transcriptional activation.

Oligonucleotides as transcription factor decoys

Cellular and molecular research has been focused to develop a means to regulate gene expression in an effort to treat and cure a variety of diseases and abnormal physiological conditions. A successful oligonucleotide-based approach has been the use of synthetic oligonucleotides containing an enhancer element that can penetrate cells, bind sequence-specific DNA-binding proteins and interfere with transcription in vivo. This review describes such decoy oligonucleotides that exhibit high affinity for a target transcription factor and successfully interfere with transcription in vivo. Evidence presented here shows that the decoy oligonucleotide technology offers great promise as a tool for defining cellular regulatory processes and for treating cancer, viral diseases and other pathological conditions.

Involvement of glucocorticoid receptor in the induction of differentiation by ginsenosides in F9 teratocarcinoma cells

We have previously reported that ginsenosides Rh1 and Rh2 induced the differentiation of F9 teratocarcinoma stem cells [Lee, Y. N., Lee, H. Y., Chung, H. Y., Kim, S. I., Lee, S. K., Park, B. C. and Kim, K. W., In vitro induction of differentiation by ginsenosides in F9 teratocarcinoma cells. Eur. J. Cancer 1996, 32, 1420-1428.]. Since the chemical structure of Rh1 and Rh2 is very similar to that of dexamethasone, a synthetic glucocorticoid, we investigated whether Rh1 and Rh2 act through the glucocorticoid receptor (GR). Immunocytochemistry showed that Rh1 or Rh2 increased the nuclear translocation of GR in the same manner of dexamethasone. In the gel shift assay, glucocorticoid response element (GRE) binding protein in F9 cells was increased by Rh1 or Rh2. To confirm whether the increased binding protein is GR, we performed the competition assay with unlabeled GRE as a specific competitor. Moreover, supershift assay with the GR antibody showed that the binding proteins are GR. In addition, to confirm the Rh1 or Rh2-induced transactivation of GRE promoter, we cotransfected GR expression vector and GRE-luciferase vector. In the luciferase assay, Rh1 or Rh2 potently induced luciferase activity and this induction was blocked by RU486, a potent GR antagonist. Taken together, we suggest that ginsenosides Rh1 and Rh2 may induce the differentiation of F9 cells by stimulating the nuclear translocation of GR.

The RIIbeta regulatory subunit of protein kinase A binds to cAMP response element: an alternative cAMP signaling pathway

cAMP, through the activation of cAMP-dependent protein kinase (PKA), is involved in transcriptional regulation. In eukaryotic cells, cAMP is not considered to alter the binding affinity of CREB/ATF to cAMP-responsive element (CRE) but to induce serine phosphorylation and consequent increase in transcriptional activity. In contrast, in prokaryotic cells, cAMP enhances the DNA binding of the catabolite repressor protein to regulate the transcription of several operons. The structural similarity of the cAMP binding sites in catabolite repressor protein and regulatory subunit of PKA type II (RII) suggested the possibility of a similar role for RII in eukaryotic gene regulation. Herein we report that RIIbeta subunit of PKA is a transcription factor capable of interacting physically and functionally with a CRE. In contrast to CREB/ATF, the binding of RIIbeta to a CRE was enhanced by cAMP, and in addition, RIIbeta exhibited transcriptional activity as a Gal4-RIIbeta fusion protein. These experiments identify RIIbeta as a component of an alternative pathway for regulation of CRE-directed transcription in eukaryotic cells.

Cloning and characterization of two catA genes in Acinetobacter lwoffii K24

Two novel type I catechol 1,2-dioxygenases inducible on aniline media were isolated from Acinetobacter lwoffii K24. Although the two purified enzymes, CD I1 and CD I2, had similar intradiol cleavage activities, they showed different substrate specificities for catechol analogs, physicochemical properties, and amino acid sequences. Two catA genes, catA1 and catA2, encoding by CD I1 and CD I2, respectively, were isolated from the A. lwoffii K24 genomic library by using colony hybridization and PCR. Two DNA fragments containing the catA1 and catA2 genes were located on separate regions of the chromosome. They contained open reading frames encoding 33.4- and 30.4-kDa proteins. The amino acid sequences of the two proteins matched well with previously determined sequences. Interestingly, further analysis of the two DNA fragments revealed the locations of the catB and catC genes as well. Moreover, the DNA fragment containing catA1 had a cluster of genes in the order catB1-catC1-catA1 while the catB2-catA2-catC2 arrangement was found in the catA2 DNA fragment. These results may provide an explanation of the different substrate specificities and physicochemical properties of CD I1 and CD I2.