lncRNA NEAT1 ameliorates LPS‑induced inflammation in MG63 cells by activating autophagy and suppressing the NLRP3 inflammasome

Abstract

The mechanisms of inflammation in bone and joint tissue are complex and involve long non-coding RNAs (lncRNAs), which play an important role in this process. The aim of the present study was to screen out differentially expressed genes in human osteoblasts stimulated by inflammation, and to further explore the mechanisms underlying inflammatory responses and the functional activity of human osteoblasts through bioinformatics methods and in vitro experiments. For this purpose, MG63 cells were stimulated with various concentrations of lipopolysaccharide (LPS) for different periods of time to construct an optimal inflammatory model and RNA sequencing was then performed on these cells. The levels of nuclear enriched abundant transcript 1 (NEAT1), various inflammatory factors, Nod-like receptor protein 3 (NLRP3) protein and osteogenesis-related proteins, as well as the levels of cell apoptosis- and cell cycle-related markers were measured in MG63 cells stimulated with LPS, transfected with NEAT1 overexpression plasmid and treated with bexarotene by western blot analysis, RT-qPCR, immunofluorescence, FISH, TEM and flow cytometry. There were 427 differentially expressed genes in the LPS-stimulated MG63 cells, in which NEAT1 was significantly downregulated. LPS upregulated the expression of inflammatory cytokines and NLRP3, inhibited the expression of autophagy-related and osteogenesis-related proteins, promoted apoptosis and altered the cell cycle, which was partially inhibited by NEAT1 overexpression and promoted by bexarotene. LPS stimulated inflammation in the MG63 cells and inhibited the retinoid X receptor (RXR)-α to downregulate the expression of NEAT1 and decrease levels of autophagy, which promoted the activation of NLRP3 and the release of inflammatory factors, and impaired the functional activity of osteoblasts, thus promoting the development of inflammation.

The expression patterns of MALAT-1, NEAT-1, THRIL, and miR-155-5p in the acute to the post-acute phase of COVID-19 disease

“…Currently, our understanding of SARS-CoV-2 processes is limited, and there are no particular biomarkers associated with SARS-CoV-2 diagnosis or therapy. Since selected cellular ncRNAs (miR-155-5p, 27 , 28 , 29 , 30 , 31 MALAT-1, 32 , 33 , 34 , 35 NEAT-1[ 20 , 36 , 37 ] and THRIL[ 38 , 39 ]) may play critical roles in immune response regulation and inflammation, we evaluated the expression pattern of lncRNAs (MALAT-1, NEAT-1 and THRIL) and miR-155-5p in Peripheral Blood Mononuclear Cells (PBMC) of SARS-CoV-2 infected individuals in both acute and post-acute stages and compared to healthy individuals.…”

MiR-27a-3p promotes the osteogenic differentiation by activating CRY2/ERK1/2 axis

“…On the other hand, cells will switch to an autophagy pathway when apoptosis is inhibited (Yu et al 2021). It was previously reported that autophagy and apoptosis were closely associated with the differentiation of osteoblasts (Dai et al 2021). Moreover, mitogen-activated protein kinase (MAPK) could regulate cell proliferation, apoptosis and differentiation (Johnson and Lapadat 2002).…”

NEAT1 Confers Radioresistance to Hepatocellular Carcinoma Cells by Inducing Autophagy through GABARAP

“…Several studies showed that NEAT1 is involved in the regulation of autophagy. NEAT1 accelerates lipopolysaccharide-induced autophagy to enhance the inflammatory response in renal fibroblast cells and osteoblast cells [ 40 , 41 ]. Conversely, NEAT1 inhibits PTEN-induced kinase 1dependent autophagy by facilitating the proteasomal degradation of NEDD4-like E3 ubiquitin-protein ligase.…”