Long noncoding RNA GAS5 promotes apoptosis in primary nucleus pulposus cells derived from the human intervertebral disc via Bcl‑2 downregulation and caspase‑3 upregulation

Abstract

Nucleus pulposus cell (NPC) apoptosis serves an important role in intervertebral disc degeneration (IDD); however, the roles of long noncoding RNAs (lncRNAs) in this process remain unknown. The present study aimed to determine the effects of the lncRNA growth arrest-specific transcript 5 (GAS5) on the apoptosis of primary human NPCs derived from the intervertebral disc, and to investigate the underlying mechanisms. TargetScan was used to predict the lncRNAs targeted by microRNA-155 (miR-155). Then, NPCs were subjected to lentivirus-mediated transduction of miR-155 or GAS5. A human lncRNA and mRNA array was used to screen differentially expressed lncRNAs following miR-155 overexpression. GAS5 and miR-155 expression levels were determined by reverse transcription-quantitative polymerase chain reaction. After GAS5 overexpression, apoptosis was assessed by flow cytometry via Annexin V/propidium iodide staining. Western blotting was employed to determine the expression of apoptosis-associated proteins, including caspase-3 and B cell lymphoma 2 (Bcl-2). TargetScan indicated GAS5 had one binding site for miR-155. Following exogenous transfection of miR-155 mimics, GAS5 expression levels in NPCs were significantly decreased (P<0.05). Interestingly, miR-155 overexpression in NPCs resulted in 721 differentially expressed lncRNAs compared with the negative control group (P<0.05), including 492 and 229 upregulated and downregulated lncRNAs respectively. In addition, 18 transcripts of GAS5 exhibited a downregulated expression profile. GAS5 overexpression in NPCs resulted in enhanced caspase-3 decreased Bcl-2 expression levels; the apoptosis of NPCs was significantly increased (P<0.05). The results of the present study revealed that overexpression of lncRNA GAS5 may promotes NPC apoptosis via Bcl-2 downregulation and caspase-3 upregulation, which may be associated with miR-155. The results of the present study suggest that lncRNA GAS5-silenced NPCs, or lentivirus-mediated lncRNA GAS5 knockdown may be precise and effective therapeutic strategies in the treatment of IDD.

Circulating Long Non-Coding RNA GAS5 Is Overexpressed in Serum from Osteoporotic Patients and Is Associated with Increased Risk of Bone Fragility

“…Vertebral fractures are the most prevalent type of osteoporotic fractures in postmenopausal women and the spine fracture status represents the most important risk factor for future fracture [ 34 ]. A recent study indicates that GAS5 upregulation is related to intervertebral disc degeneration due to its proapoptotic effects [ 19 ]. We also found the most significant GAS5 upregulation in OP_VF with respect to OP_FF.…”

“…This polymorphism is capable of modulating Gas5 expression level and has been associated with the susceptibility to several cancer types [ 15 , 16 , 17 ]. GAS5 has been demonstrated to regulate inflammation, proliferation and apoptosis in different pathological conditions [ 14 , 18 , 19 ]. Although the actions of GAS5 are not completely elucidated, some mechanisms have been proposed [ 13 , 20 ].…”

“…For instance, GAS5 is predicted to inhibit miR-21, which also regulates osteoclast formation [ 14 ], and, in turn, miR-21 is capable of suppressing GAS5 expression in a reciprocal feedback loop [ 21 , 22 ]. Besides, Wang and colleagues have observed that GAS5 overexpression in nucleus pulpus cells repressed Bcl-2 and upregulated caspase-3, suggesting lncRNA GAS5 is a potential therapeutic target for intervertebral disc degeneration [ 19 ]. Recently, GAS5 deregulation was also found in human multipotential mesenchymal stem cells (hMSCs) derived from OP patients and in serum from postmenopausal osteoporotic women [ 23 , 24 ].…”

lncRNA and Mechanisms of Drug Resistance in Cancers of the Genitourinary System

“…Inversely, upregulation of Bcl-2 reversed the inhibitory effect of GAS5 on chemoresistance to doxorubicin in chemo resistant cells [32]. This is no surprise, as GAS5 is notably known for apoptosis promotion, mainly via Bcl-2 suppression and caspase-3 upregulation, which is possibly facilitated through the miR-155 regulatory pathway [134].…”

Non-Coding RNAs in Cartilage Development: An Updated Review

“…It has been suggested that ncRNAs can be used for diagnosis and prognosis of cartilage-pertinent diseases, and might also be exploited as potential therapeutic agents to stop and even reverse the disease progression. Some studies asserted that inhibition of GAS5 will suppress cell apoptosis and probably can be used as a therapeutic agent [182]. It has been detected that exosomes derived from miR-140–5p-overexpressing human synovial MSCs promote cartilage tissue regeneration and prevent OA of the knee in a rat model [183].…”