Differential gene expression in brain tissues of aggressive and non-aggressive dogs

<p>Abstract</p> <p>Background</p> <p>Canine behavioural problems, in particular aggression, are important reasons for euthanasia of otherwise healthy dogs. Aggressive behaviour in dogs also represents an animal welfare problem and a public threat. Elucidating the genetic background of adverse behaviour can provide valuable information to breeding programs and aid the development of drugs aimed at treating undesirable behaviour. With the intentions of identifying gene-specific expression in particular brain parts and comparing brains of aggressive and non-aggressive dogs, we studied amygdala, frontal cortex, hypothalamus and parietal cortex, as these tissues are reported to be involved in emotional reactions, including aggression. Based on quantitative real-time PCR (qRT-PCR) in 20 brains, obtained from 11 dogs euthanised because of aggressive behaviour and nine non-aggressive dogs, we studied expression of nine genes identified in an initial screening by subtraction hybridisation.</p> <p>Results</p> <p>This study describes differential expression of the <it>UBE2V2 </it>and <it>ZNF227 </it>genes in brains of aggressive and non-aggressive dogs. It also reports differential expression for eight of the studied genes across four different brain tissues (amygdala, frontal cortex, hypothalamus, and parietal cortex). Sex differences in transcription levels were detected for five of the nine studied genes.</p> <p>Conclusions</p> <p>The study showed significant differences in gene expression between brain compartments for most of the investigated genes. Increased expression of two genes was associated with the aggression phenotype. Although the <it>UBE2V2 </it>and <it>ZNF227 </it>genes have no known function in regulation of aggressive behaviour, this study contributes to preliminary data of differential gene expression in the canine brain and provides new information to be further explored.</p

Radon-220 diffusion from 224Ra-labeled calcium carbonate microparticles: Some implications for radiotherapeutic use.

Alpha-particle emitting radionuclides continue to be the subject of medical research because of their high energy and short range of action that facilitate effective cancer therapies. Radium-224 (224Ra) is one such candidate that has been considered for use in combating micrometastatic disease. In our prior studies, a suspension of 224Ra-labeled calcium carbonate (CaCO3) microparticles was designed as a local therapy for disseminated cancers in the peritoneal cavity. The progenies of 224Ra, of which radon-220 (220Rn) is the first, together contribute three of the four alpha particles in the decay chain. The proximity of the progenies to the delivery site at the time of decay of the 224Ra-CaCO3 microparticles can impact its therapeutic efficacy. In this study, we show that the diffusion of 220Rn was reduced in labeled CaCO3 suspensions as compared with cationic 224Ra solutions, both in air and liquid volumes. Furthermore, free-floating lead-212 (212Pb), which is generated from released 220Rn, had the potential to be re-adsorbed onto CaCO3 microparticles. Under conditions mimicking an in vivo environment, more than 70% of the 212Pb was adsorbed onto the CaCO3 at microparticle concentrations above 1 mg/mL. Further, the diffusion of 220Rn seemed to occur whether the microparticles were labeled by the surface adsorption of 224Ra or if the 224Ra was incorporated into the bulk of the microparticles. The therapeutic benefit of differently labeled 224Ra-CaCO3 microparticles after intraperitoneal administration was similar when examined in mice bearing intraperitoneal ovarian cancer xenografts. In conclusion, both the release of 220Rn and re-adsorption of 212Pb are features that have implications for the radiotherapeutic use of 224Ra-labeled CaCO3 microparticles. The release of 220Rn through diffusion may extend the effective range of alpha-particle dose deposition, and the re-adsorption of the longer lived 212Pb onto the CaCO3 microparticles may enhance the retention of this nuclide in the peritoneal cavity

Biodistribution of ¹⁷⁷Lu-OI-3 variants in mice bearing OHS xenografts.

<p>Comparison of biodistribution of ¹⁷⁷Lu-labeled murine OI-3, chimeric IgG1 OI-3 (CHOI-3.1) and chimeric IgG3 OI-3 (CHOI-3.3) in nude mice with OHS osteosarcoma xenografts. The data are presented as percentage of injected dose per gram tissue at 24 (A) and 48 hours (B) after injection, with error bars corresponding to the standard error of the mean. Three to six mice were used in each group, giving four to eight tumors per time point.</p

Biodistribution of ¹⁷⁷Lu-CHOI-3.1 in mice bearing OHS xenografts.

<p>Biodistribution of ¹⁷⁷Lu-labeled chimeric OI-3 IgG1 isotype antibody (CHOI-3.1) in tissues of interest in OHS xenograft-carrying nude mice. At each time point from three to six animals were used, with number of tumors ranging from five to twelve per group. Straight lines have been drawn to connect the data points. The error bars correspond to the standard error of the mean.</p

CD146 expression in human osteosarcoma cell lines.

<p>A representative flow cytometry histogram that compare the binding of murine anti-CD146 OI-3 antibody to three different human osteosarcoma cell lines: OHS (A), Saos-2 (B) and KPDX (C). Control samples are unstained cells and cells stained only with the FITC-conjugated secondary antibody (ab). In addition, the binding of murine anti-CD37 antibody HH1 was examined for OHS (A) and Saos-2 (B) cells. The samples were analyzed on a BD FacsCalibur.</p

Comparison of the binding ability of chimeric antibodies targeting different antigens on OHS cells.

<p>A representative flow cytometry histogram which shows binding of the chimeric versions of OI-3 to OHS cells, compared with samples incubated with cetuximab, trastuzumab and rituximab. Control samples are unstained cells and cells stained only with the FITC-conjugated secondary antibody (ab). The samples were run on a Guava EasyCyte HT. Take note that the samples with chimeric antibodies were run on a different platform, with different settings and secondary antibody, and the fluorescence intensity levels are therefore not directly comparable to runs with murine OI-3 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0165382#pone.0165382.g001" target="_blank">Fig 1</a>.</p

Biodistribution of ¹²⁵I-labeled antibodies in mice bearing OHS xenografts.

<p>Tumor to normal tissue ratios 24 hours after injection of ¹²⁵I-labeled antibodies in female nude mice bearing OHS tumor xenografts. Four to five animals were used for each radioimmunoconjugate, which gave from four to seven tumors per group. Error bars correspond to standard error of the mean.</p

Absorbed radiation doses to normal tissues and tumors.

<p>Estimated absorbed radiation dose (Gy) to normal tissues and tumors for nude mice with OHS osteosarcoma xenografts after intravenous injection of ¹⁷⁷Lu-labeled chimeric OI-3 IgG1 isotype antibody (CHOI-3.1). The data were normalized to an injected activity of 1 MBq per mouse. Error bars correspond to standard deviation.</p