Experimental study on effect of simulated microgravity on structural chromosome instability of human peripheral blood lymphocytes.

Lijun Wei,Yufeng Liu,Shuliang Shi,Yu Li,Qiong Wu,Li Kang,Chuanpeng Liu,Kamaleshwar Singh

doi:10.1371/journal.pone.0100595

Abstract

Experimental study was made by keeping human peripheral blood lymphocytes under simulated microgravity in a Rotary Cell Culture System bioreactor to investigate the changes that occur in the number of chromosomes, the expression rate of chromosome fragile site, and the expressions of DNA replication- and repair-related genes. Experimental results indicate simulated microgravity has no effect on the numerical chromosome instability of human peripheral blood lymphocytes, but it enhances the structural chromosome instability of human peripheral blood lymphocytes through the inhibition of DNA replication and the reduction of DNA repair. So, the mechanism of chromosome fragile site induced by simulated microgravity can be explained using the changes that occur in the chromosome structure of human peripheral blood lymphocytes, the DNA replication and repair under the effect of simulated microgravity.

Highlights

Chromosome instability (CIN) is a great concern for mannedspace flight because of the space environment-induced damages to human chromosomes observed in the lymphocytes of Astronauts [1]
The number of chromosomes does not change under different culture conditions, and so, simulated microgravity has no effect on the numerical chromosome instability of human peripheral blood lymphocytes (PBL) cells
There is no chromosome gain or loss of a whole chromosome. It can be seen from the research results that none of the culture conditions used for this study shows any effect on the chromosome segregation of human PBL cells, i.e. simulated microgravity has no effect on the numerical chromosome instability of human PBL cells

Summary

Introduction

Chromosome instability (CIN) is a great concern for mannedspace flight because of the space environment-induced damages to human chromosomes observed in the lymphocytes of Astronauts [1]. Structural and numerical chromosome instabilities are the two aspects of CIN commonly observed in solid tumors [2,3]. The numerical chromosome instability is known as aneuploid, and the structural chromosome instability means deletion, inversion, translocation and rearrangement of chromosomes [4,5]. Chromosome fragile sites are specific loci that preferentially exhibit gaps and breaks in metaphase chromosomes after DNA synthesis is partially inhibited [6]. Breaks may cause deletion of chromosome, fragmentation without centromere and enhancement of chromosome aberration [7]. The expression of chromosome fragile site is closely related to chromosome aberration

Methods

Results

Conclusion