Transcriptional Response in Human Jurkat T Lymphocytes to a near Physiological Hypergravity Environment and to One Common in Routine Cell Culture Protocols

Abstract

Cellular effects of hypergravity have been described in many studies. We investigated the transcriptional dynamics in Jurkat T cells between 20 s and 60 min of 9 g hypergravity and characterized a highly dynamic biphasic time course of gene expression response with a transition point between rapid adaptation and long-term response at approximately 7 min. Upregulated genes were shifted towards the center of the nuclei, whereby downregulated genes were shifted towards the periphery. Upregulated gene expression was mostly located on chromosomes 16–22. Protein-coding transcripts formed the majority with more than 90% of all differentially expressed genes and followed a continuous trend of downregulation, whereas retained introns demonstrated a biphasic time-course. The gene expression pattern of hypergravity response was not comparable with other stress factors such as oxidative stress, heat shock or inflammation. Furthermore, we tested a routine centrifugation protocol that is widely used to harvest cells for subsequent RNA analysis and detected a huge impact on the transcriptome compared to non-centrifuged samples, which did not return to baseline within 15 min. Thus, we recommend carefully studying the response of any cell types used for any experiments regarding the hypergravity time and levels applied during cell culture procedures and analysis.

Increased H3K9me3 and F-Actin Reorganization in the Rapid Adaptive Response to Hypergravity in Human T Lymphocytes

“…Interestingly, H3K9me3 changes appear to be linked to distinct mechanistic processes, potentially influenced by force-induced chromatin remodeling mediated by LINC components [85,86]. The experiment revealed maximal H3K9me3 levels after 15 min hypergravity, coinciding with gene expression downregulation observed in previous transcriptomics analyses under similar conditions [24,87]. However, after 1 h of centrifugation, H3K9me3 returned to control values, suggesting a homeostatic adaptation.…”

“…Furthermore, experiments have shown that transcriptome changes in Jurkat T lymphocytes exposed to hypergravity during suborbital rocket experiments can be replicated using an experimental centrifuge on the ground at 9× g [23]. Our previous research has also observed changes in histone modifications in Jurkat T lymphocytes [24] and cytoskeletal structures in human primary macrophages [25]. It is unknown by which means cells sense gravitational forces, but it is hypothesized that, as a mechanical force, gravity is transduced into the nucleus via the cytoskeleton, potentially changing nuclear structure, chromatin organization and subsequently transcription [26].…”

Digitalized organoids: integrated pipeline for 3D high-speed analysis of organoid structures using multilevel segmentation and cellular topology

“…This void is particularly striking given the contemporary surge of interest in space biology and the concurrent application of organoids in space-related extreme conditions 23–25 . Earlier deployments of biological experiments in parabolic flight have yielded some first insights into the immediate effects on cellular adhesion but only within a 2D cellular monolayer 26–28 . The dataset used here is thus firmly situated within the methodological framework of inquiry driven by discovery.…”

“…Earlier deployments of biological experiments in parabolic flight have yielded some first insights into the immediate effects on cellular adhesion but only within a 2D cellular monolayer 26 - 28 . The dataset used here is thus firmly situated within the methodological framework of inquiry driven by discovery.…”