Evaluation of Pm2.5 Influence on Human Lung Cancer Cells Using a Microfluidic Platform.

In this study, we developed a microfluidic device that is able to monitor cell biology under continuous PM2.5 treatment. The effects of PM2.5 on human alveolar basal epithelial cells, A549 cells, and uncovered several significant findings were investigated. The results showed that PM2.5 exposure did not lead to a notable decrease in cell viability, indicating that PM2.5 did not cause cellular injury or death. However, the study found that PM2.5 exposure increased the invasion and migration abilities of A549 cells, suggesting that PM2.5 might promote cell invasiveness. Results of RNA sequencing revealed 423 genes that displayed significant differential expression in response to PM2.5 exposure, with a particular focus on pathways associated with the generation of reactive oxygen species (ROS) and mitochondrial dysfunction. Real-time detection demonstrated an increase in ROS production in A549 cells after exposure to PM2.5. JC1 assay, which indicated a loss of mitochondrial membrane potential (ΔΨm) in A549 cells exposed to PM2.5. The disruption of mitochondrial membrane potential further supports the detrimental effects of PM2.5 on A549 cells. These findings highlight several adverse effects of PM2.5 on A549 cells, including enhanced invasion and migration capabilities, altered gene expression related to ROS pathways, increased ROS production and disruption of mitochondrial membrane potential. These findings contribute to our understanding of the potential mechanisms through which PM2.5 can impact cellular function and health.

CCL2 associated with CD38 expression during ex vivo expansion in human cord blood-derived hematopoietic stem cells.

To date, different experimental strategies have been developed for the ex vivo expansion of human hematopoietic stem cells (HSCs) for clinical applications. However, differences in the genomic function of expanded HSCs under different culture systems remain unclear. In this study, we compared the gene expression profiles of HSCs in ex vivo expanded serum (10% FBS, fetal bovine serum) and serum-free culture systems and analyzed the molecular functions of differentially expressed genes using microarray chips. We identified 839 differentially expressed genes between the two culture systems. These genes were enriched in the TNF -regulated inflammatory pathway in an FBS culture system. In addition, the mRNA expression of CCL2 (C-C motif chemokine ligand 2), TNF (tumor necrosis factor) and FOS (FBJ murine osteosarcoma viral oncogene homolog) was validated by RT-qPCR. Our data revealed that ex vivo expansion of HSCs using the FBS culture system induces an inflammatory response and high CD38 expression, indicating that this system might activate an inflammatory pathway and induce expression of the cancer marker CD38 during ex vivo expansion of HSCs. This study provides a transcriptional profile and new insights into the genomic functions of HSCs under different expanded cultures.

Systems biology approach to exploring the effect of cyclic stretching on cardiac cell physiology.

Although mechanical forces are involved in pressure-overloaded cardiomyopathy, their effects on gene transcription profiles are not fully understood. Here, we used next-generation sequencing (NGS) to investigate changes in genomic profiles after cyclic mechanical stretching of human cardiomyocytes. We found that 85, 87, 32, 29, and 28 genes were differentially expressed after 1, 4, 12, 24, and 48 hours of stretching. Furthermore, 10 of the 29 genes that were up-regulated and 11 of the 28 that were down-regulated after 24 h showed the same changes after 48 h. We then examined expression of the genes that encode serpin family E member 1 (SERPINE1), DNA-binding protein inhibitor 1 (ID1), DNA-binding protein inhibitor 3 (ID3), and CCL2, a cytokine that acts as chemotactic factor in monocytes, in an RT-PCR experiment. The same changes were observed for all four genes after all cyclic stretching durations, confirming the NGS results. Taken together, these findings suggest that cyclical stretching can alter cardiac cell physiology by activating cardiac cell metabolism and impacting cholesterol biosynthesis signaling.

Influence of sex differences in leaders' behavior.

Sex differences in influence tactics were examined with a sample of 269 followers (67 men, 202 women) at a large midwestern national insurance company who rated the downward influence tactics used by their direct supervisors. Downward influence tactics are behaviors used by leaders to gain compliance from followers. One department within the organization was identified as a source for participants in the study. Participation was voluntary. The age range for the sample was 21 to 65 years, with the largest percentage falling in the 40-49 year range (M = 3.8, SD = .8). Hierarchical linear modeling procedures were utilized to analyze the multiple level data (leader and follower) and to examine variables within the organization at different levels of analysis. Leader participants were asked to solicit their followers to complete an influence tactic measure, which consisted of the most reliable subscales taken from the Influence Behavior Questionnaire, Schriesheim and Hinkin Influence Measure, and the Profiles of Organizational Influence Strategies. The integrated measure resulted in a 45-item scale. It was hypothesized that, overall, followers would report that male leaders would use hard influence tactics more frequently than female leaders. On the other hand, followers would report that female leaders would use soft influence tactics more frequently than male leaders. When differentiating followers by sex, however, we expected that male followers would report more than female followers that their leaders use hard tactics more frequently. Also, we expected that female followers would report (more than male followers) that their leaders use soft tactics more frequently. Overall, followers reported that male leaders used significantly more personal appeal and consultation, so called "soft tactics," with their followers than did female leaders. Female followers reported that their leaders (both male and female) used consultation and inspirational appeal more frequently. In contrast, male followers reported that their leaders used exchange, so called "hard tactics," more frequently.