Intracellular differential gene expression detected by transcriptome sequencing after lactate treatment of nucleus pulposus cells

ABSTRACT: The accumulation of metabolites in the intervertebral disc is regarded as an important inducement of intervertebral disc degeneration (IVDD). Lactate, a metabolite produced by the cellular anaerobic glycolysis process, has been proved to be closely associated with IVDD. However, little was known about the role of lactate in nucleus pulposus cells (NPCs) senescence. This study attempted to investigate the effect and molecular mechanism of lactate on NPCs senescence in vitro and in vivo. A puncture-induced disc degeneration model was established in rats. Metabolomics analysis proved that lactate was significantly increased in the rat degenerated intervertebral disc. Eliminating extra lactate using lactate oxidase (LOx)-overexpressing lentivirus alleviated the progression of IVDD. In vitro experiments showed that high concentration lactate could induce senescence and oxidative stress in NPCs. High-throughput RNA sequencing (RNA-seq) results and bioinformatic analysis exhibited that lactate-stimulated NPCs senescence may be related to the PI3K/Akt signaling pathway. Further study verified that high concentration lactate could induce NPCs senescence and oxidative stress via inhibiting PI3K/Akt signaling and downstream Akt/p21/p27/cyclinD1 and Akt/Nrf2/HO-1 pathway. Utilizing molecular docking, we found that lactate may suppress the Akt phosphoactivation via binding to Lys39 and Leu52 in the PH domain of Akt. In conclusion, this study illuminates that lactate could promote the senescence of NPCs to aggravate IVDD by suppressing the PI3K/Akt signaling pathway and the expression of its downstream genes. These results highlight the involvement of lactate NPCs senescence, which may become a novel potential therapeutic target for the treatment of IVDD.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE219145 | GEO | 2022/12/06

REPOSITORIES: GEO