Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on spontaneous movement of human neuroblastoma cells

Aryl hydrocarbon receptor (AhR) plays important roles in the interferences of dioxin exposure with the occurrence and development of tumors. Neuroblastoma is a kind of malignant tumor with high mortality and its occurrence is getting higher in dioxin exposed populations. However, there is still a lack of direct evidence of influences of dioxin on neuroblastoma cell migration. SK-N-SH is a human neuroblastoma cell line which has been used to reveal 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced dysregulation of certain promigratory gene. Thus, in this study, we employed SK-N-SH cells to investigate the effects of TCDD on the spontaneous movement of neuroblastoma cells, which is a short-range cell migratory behavior related to clone formation and tumor metastasis in vitro. Using unlabeled live cell imaging and high content analysis, we characterized the spontaneous movement under a full-nutrient condition in SK-N-SH cells. We found that the spontaneous movement of SK-N-SH cells was inhibited after 36- or 48-h treatment with TCDD at relative low concentrations (10^-10 or 2 × 10^-10 M). The TCDD-treated cells were unable to move as freely as that of control cells, resulting in less diffusive trajectories and a decreased displacement of the movement. In line with this cellular effect, the expression of pro-adhesive genes was significantly induced in time- and concentration-dependent manners after TCDD treatment. In addition, with the presence of AhR antagonist, CH223191, the effects of TCDD on the gene expression and the spontaneous cell movement were effectively reversed. Thus, we proposed that AhR-mediated up-regulation of pro-adhesive genes might be involved in the inhibitory effects of dioxin on the spontaneous movement of neuroblastoma cells. To our knowledge, this is the first piece of direct evidence about the influence of dioxin on neuroblastoma cell motility.

The effect of personality measurement conditions on spontaneous swimming behavior in the pale chub Zacco platypus (Cyprinidae)

Studies on personality have revealed that some personality traits are strongly correlated; thus, researchers may be able to acquire data for variables related to different personality traits from one measurement. Therefore, the aim of the present study was to test whether spontaneous movement traits used in fish personality measurements are correlated or vary among different contexts in a common Chinese cyprinid fish, the pale chub (Zacco platypus, Cyprinidae). The median swimming speed, percent time spent moving and median turning rate were measured in a boldness context (with a shelter available), then in an exploration context (with a novel object nearby) and finally in a control context (i.e., with no shelter or novel object). The median swimming speed, percent time spent moving, and median turning rate all showed positive correlations between the control and the other two contexts, which suggests that future studies might use spontaneous swimming variables measured in exploration or boldness contexts to avoid the need to carry out a separate activity test. Further analysis comparing the distance to and latency to explore the novel object between the exploration context (with the novel object present) and control context (with an imaginary object at the same position) showed that the amount of time it took for the fish to first reach the object for exploration was significantly shorter in an exploration context than in a control context. This suggests that latency to explore might be useful as a variable indicating exploration in the pale chub in the future.

Spontaneous movements in the first four months of life: An accelerometric study in moderate and late preterm infants

BACKGROUND

Moderate preterm infants (MPI) and late preterm infants (LPI) account for the majority of children born preterm. Up to 5% of MPI and LPI are estimated to manifest neurodevelopmental impairments. However, information about normal early motor development in these patients is lacking.

AIM

To find characteristic patterns for motor development in the first four months of life among MPI and LPI without risk factors for developmental impairment by using accelerometry of spontaneous movements.

STUDY DESIGN

Prospective and observational study.

SUBJECTS

Twenty-three MPI and LPI (9 female, 14 male) without known risk factors for neurodevelopmental impairment were included in this study. Spontaneous movements were measured by accelerometry at the time of hospital discharge (mean: 36.6wks postmenstrual age (PMA)) and at the corrected age of three months (mean: 53.0wks PMA).

OUTCOME MEASURES

Motor development was described by analyzing 36 parameters calculated from the acceleration signal. Normal neurodevelopmental outcome was confirmed by Bayley Scales of Infant Development at the corrected age of two years.

RESULTS

Statistically significant differences (p < 0.05) between the two measurements could be shown in 26 out of the 36 parameters. Striking changes in motor development were an increase in acceleration and variability of the spontaneous movements, the main criterion for analyzing spontaneous movements. Furthermore, the regularity of spontaneous movements increased significantly.

CONCLUSION

Characteristic patterns of normal motor development in MPI and LPI can be identified and provide a basis for future investigations aiming at the early detection of abnormal motor development for this specific patient group.

Developmental toxicity and neurotoxicity of two matrine-type alkaloids, matrine and sophocarpine, in zebrafish (Danio rerio) embryos/larvae

Matrine and sophocarpine are two major matrine-type alkaloids included in the traditional Chinese medicine (TCM) Kushen (the root of Sophora flavescens Ait.). They have been widely used clinically in China, however with few reports concerning their potential toxicities. This study investigated the developmental toxicity and neurotoxicity of matrine and sophocarpine on zebrafish embryos/larvae from 0 to 96/120h post fertilization (hpf). Both drugs displayed teratogenic and lethal effects with the EC50 and LC50 values at 145 and 240mg/L for matrine and 87.1 and 166mg/L for sophocarpine, respectively. Exposure of matrine and sophocarpine significantly altered spontaneous movement and inhibited swimming performance at concentrations below those causing lethality and malformations, indicating a neurotoxic potential of both drugs. The results are in agreement with most mammalian studies and clinical observations.