Global transcriptomic analysis of simulated microgravity on MLO-Y4 osteocytic cells.

Disuse osteoporosis is a metabolic bone disease resulted from skeletal unloading (e.g., extended bed rest, limb immobilization, and spaceflight), and the slow and insufficient bone recovery during reambulation remains an unresolved medical challenge. Here, we investigated the glutamine supplementation or PDK1 inhibition can accelerate bone recovery after long-duration disuse/unloading by specifically modulating osteocytes. We performed RNA-seq on MLO-Y4 cells exposed or unexposed to simulated microgravity for 48 hours. The total RNA of MLO-Y4 was collected using an RNA isolation kit (#TR205, Beijing Tianmo Biotechnology, China), and then paired-end libraries were synthesized by using the TruSeqTM RNA sample preparation kit (Illumina, USA). Following purification, the mRNA was fragmented into small pieces and the cleaved RNA fragments were conversed to cDNA. The products were then purified and enriched with PCR to create the final cDNA library. After cluster generation, the libraries were sequenced using an Illumina NovaSeq 6000 platform (Illumina, USA).