Oct-3/4 promotes migration and invasion of glioblastoma cells

As a result of increased glioblastoma migration and invasion into normal brain parenchyma, treatment of local tumor recurrence following initial treatment in glioblastoma patients remains challenging. Recent studies have demonstrated increased Oct-3/4 expression, a self-renewal regulator in stem cells, in glioblastomas. However, little is known regarding the influence of Oct-3/4 in glioblastoma cell invasiveness. The present study established Oct-3/4-overexpressing glioblastoma cells, which were prepared from human glioblastoma patients, to assess migration, invasion, and mRNA expression profiles of integrins and matrix metalloproteinases (MMPs). Compared with control cells, Oct-3/4 expressing-glioblastoma cells exhibited increased migration and invasion in wound healing and Matrigel invasion assays. Oct-3/4 overexpression resulted in upregulated FAK and c-Src expression, which mediate integrin signals. Vinculin accumulated along the leading edges of Oct-3/4 expressing-glioblastoma cells and associated with membrane ruffles during cell migration. Oct-3/4 expressing-cells exhibited increased MMP-13 mRNA expression and MMP-13 knockdown by shRNA suppressed cell invasion into Matrigel and organotypic brain slices. These results suggested that Oct-3/4 enhanced degradation of surrounding extracellular matrix by increasing MMP-13 expression and altering integrin signaling. Therefore, Oct-3/4 might contribute to tumor promoting activity in glioblastomas.     

Gamma delta T cells kill myeloma cells by sensing mevalonate metabolites and ICAM-1 molecules on cell surface

We evaluated the mechanism of recognition of myeloma cells by γδT cells. The expanded γδT cells killed RPMI8226 and U266 myeloma cells in a γδT-cell dose-dependent manner. Pretreatment of myeloma cells with zoledronic acid or mevastatin showed that γδT cells kill myeloma cells by recognizing the mevalonate metabolites. The expression level of intercellular cell adhesion molecule-1 (ICAM-1) on myeloma cells correlates with the cytotoxicity by γδT cells. Pretreatment of RPMI8226 and U266 with an anti-ICAM-1 monoclonal antibody inhibited their cytolysis. Moreover, AMO-1 myeloma cells transfected with of human ICAM-1 cDNA were susceptible to γδT cells compared to parental AMO-1 cells. In conclusion, γδT cells recognize the mevalonate metabolites and ICAM-1 on myeloma cells.     

Antagonism of morphine-induced central respiratory depression by donepezil in the anesthetized rabbit

Morphine is often used in cancer pain and postoperative analgesic management but induces respiratory depression. Therefore, there is an ongoing search for drug candidates that can antagonize morphine-induced respiratory depression but have no effect on morphine-induced analgesia. Acetylcholine is an excitatory neurotransmitter in central respiratory control and physostigmine antagonizes morphine-induced respiratory depression. However, physostigmine has not been applied in clinical practice because it has a short action time, among other characteristics. We therefore asked whether donepezil (a long-acting acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease) can antagonize morphine-induced respiratory depression. Using the anesthetized rabbit as our model, we measured phrenic nerve discharge as an index of respiratory rate and amplitude. We compared control indices with discharges after the injection of morphine and after the injection of donepezil. Morphine-induced depression of respiratory rate and respiratory amplitude was partly antagonized by donepezil without any effect on blood pressure and end-tidal C02. In the other experiment, apneic threshold PaC02 was also compared. Morphine increased the phrenic nerve apnea threshold but this was antagonized by donepezil. These findings indicate that systemically administered donepezil partially restores morphine-induced respiratory depression and morphine-deteriorated phrenic nerve apnea threshold in the anesthetized rabbit.     

Mechanism of Suppression of Chromosomal Instability by DNA Polymerase POLQ

Although a defect in the DNA polymerase POLQ leads to ionizing radiation sensitivity in mammalian cells, the relevant enzymatic pathway has not been identified. Here we define the specific mechanism by which POLQ restricts harmful DNA instability. Our experiments show that Polq-null murine cells are selectively hypersensitive to DNA strand breaking agents, and that damage resistance requires the DNA polymerase activity of POLQ. Using a DNA break end joining assay in cells, we monitored repair of DNA ends with long 3′ single-stranded overhangs. End joining events retaining much of the overhang were dependent on POLQ, and independent of Ku70. To analyze the repair function in more detail, we examined immunoglobulin class switch joining between DNA segments in antibody genes. POLQ participates in end joining of a DNA break during immunoglobulin class-switching, producing insertions of base pairs at the joins with homology to IgH switch-region sequences. Biochemical experiments with purified human POLQ protein revealed the mechanism generating the insertions during DNA end joining, relying on the unique ability of POLQ to extend DNA from minimally paired primers. DNA breaks at the IgH locus can sometimes join with breaks in Myc, creating a chromosome translocation. We found a marked increase in Myc/IgH translocations in Polq-defective mice, showing that POLQ suppresses genomic instability and genome rearrangements originating at DNA double-strand breaks. This work clearly defines a role and mechanism for mammalian POLQ in an alternative end joining pathway that suppresses the formation of chromosomal translocations. Our findings depart from the prevailing view that alternative end joining processes are generically translocation-prone.     

Genome-Wide Association Studies Using Haplotypes and Individual SNPs in Simmental Cattle

Recent advances in high-throughput genotyping technologies have provided the opportunity to map genes using associations between complex traits and markers. Genome-wide association studies (GWAS) based on either a single marker or haplotype have identified genetic variants and underlying genetic mechanisms of quantitative traits. Prompted by the achievements of studies examining economic traits in cattle and to verify the consistency of these two methods using real data, the current study was conducted to construct the haplotype structure in the bovine genome and to detect relevant genes genuinely affecting a carcass trait and a meat quality trait. Using the Illumina BovineHD BeadChip, 942 young bulls with genotyping data were introduced as a reference population to identify the genes in the beef cattle genome significantly associated with foreshank weight and triglyceride levels. In total, 92,553 haplotype blocks were detected in the genome. The regions of high linkage disequilibrium extended up to approximately 200 kb, and the size of haplotype blocks ranged from 22 bp to 199,266 bp. Additionally, the individual SNP analysis and the haplotype-based analysis detected similar regions and common SNPs for these two representative traits. A total of 12 and 7 SNPs in the bovine genome were significantly associated with foreshank weight and triglyceride levels, respectively. By comparison, 4 and 5 haplotype blocks containing the majority of significant SNPs were strongly associated with foreshank weight and triglyceride levels, respectively. In addition, 36 SNPs with high linkage disequilibrium were detected in the GNAQ gene, a potential hotspot that may play a crucial role for regulating carcass trait components.     

Functional analysis of the Hikeshi-like protein and its interaction with HSP70 in Arabidopsis

Heat shock proteins (HSPs) refold damaged proteins and are an essential component of the heat shock response. Previously, the 70 kDa heat shock protein (HSP70) has been reported to translocate into the nucleus in a heat-dependent manner in many organisms. In humans, the heat-induced translocation of HSP70 requires the nuclear carrier protein Hikeshi. In the Arabidopsis genome, only one gene encodes a protein with high homology to Hikeshi, and we named this homolog Hikeshi-like (HKL) protein. In this study, we show that two Arabidopsis HSP70 isoforms accumulate in the nucleus in response to heat shock and that HKL interacts with these HSP70s. Our histochemical analysis revealed that HKL is predominantly expressed in meristematic tissues, suggesting the potential importance of HKL during cell division in Arabidopsis. In addition, we show that HKL regulates HSP70 localization, and HKL overexpression conferred thermotolerance to transgenic Arabidopsis plants. Our results suggest that HKL plays a positive role in the thermotolerance of Arabidopsis plants and cooperatively interacts with HSP70.     

Chelation of calcium ions by poly(gamma-glutamic acid) from Bacillus subtilis(chungkookjang)

Many studies have clarified that poly(gamma-glutamic acid) (PGA) increases the solubility of Ca(2+), suggesting that PGA enhances calcium absorption in small intestine. However, there has been no report on the specific interaction between PGA and Ca(2+) in water. We studied the aqueous solution properties of PGA calcium salt (PGA-Ca complex). The chelating ability and binding strength of PGA for Ca(2+) were evaluated. PGA-Ca complex was soluble in water in contrast with the insolubility of poly(acrylic acid) (PAA) calcium salt and the chelating ability of PGA for Ca(2+) was almost the same than that of PAA. The globular conformation of PGA-Ca complex in water was estimated by SEC and viscosity measurements. The chelation of PGA for Ca(2+) was examined by 1H NMR. The present study showing the characteristics of PGA-Ca complex will provide useful information of the calcium absorption by PGA in vivo.     

Usp46, encoding a ubiquitin specific peptidase,is a quantitative trait gene underlying “behavioral despair” in mice

Sleep and Biological Rhythms - CS mice exhibit several distinct phenotypes of circadian behavioral rhythms and sleep properties. Because many mental illnesses are associated with abnormalities in...