LncRNA MAGI2-AS3 is down-regulated in intervertebral disc degeneration and participates in the regulation of FasL expression in nucleus pulposus cells

LncRNA MAGI2-AS3 promotes fracture healing through downregulation of miR-223-3p

BACKGROUND

Long non-coding RNAs (LncRNAs) are recognized as a pivotal element in the processes of fracture healing and the osteogenic differentiation of stem cells. This study investigated the molecular mechanism and regulatory significance of lncRNA MAGI2-AS3 (MAGI2-AS3) in fracture healing.

METHODS

Serum levels of MAGI2-AS3 in patients with normal and delayed fracture healing were verified by RT-qPCR assays. The predictive efficacy of MAGI2-AS3 for delayed fracture healing was analyzed by ROC curve. Osteogenic markers were quantified by RT-qPCR assays. MC3T3-E1 cell viability was detected using CCK-8 assay, and flow cytometry was utilized to measure cell apoptosis. The dual-luciferase reporter gene assay was used to determine the targeted binding between MAGI2-AS3 and miR-223-3p.

RESULTS

Serum MAGI2-AS3 expression was decreased in patients with delayed fracture healing compared with patients with normal healing. Elevated MAGI2-AS3 resulted in an upregulation of the proliferative capacity of MC3T3-E1 cells and a decrease in mortality, along with increased levels of both osteogenic markers. However, after transfection silencing MAGI2-AS3, the trend was reversed. Additionally, miR-223-3p was the downstream target of MAGI2-AS3 and was controlled by MAGI2-AS3. miR-223-3p mimic reversed the promoting effects of MAGI2-AS3 overexpression on osteogenic marker levels and cell growth, and induced cell apoptosis.

CONCLUSION

The upregulation of MAGI2-AS3 may expedite the healing of fracture patients by targeting miR-223-3p, offering a novel biomarker for diagnosing patients with delayed healing.

Role of MAGI2-AS3 in malignant and non-malignant disorders

MAGI2 Antisense RNA 3 (MAGI2-AS3) is a long non-coding RNA (lncRNA) transcribed from a locus on 7q21.11. This lncRNA has been described to be abnormally expressed in a variety of malignancies in correlation with many clinical characteristics. Moreover, it might participate in the pathogenesis of congenital diaphragmatic hernia, Alzheimer's disease and intervertebral disc degeneration. Mechanistically, MAGI2-AS3 can serve as a molecular sponge for miR-142-3p, miR-424-5p, miR-15b, miR-233, miR-452-5p, miR-629-5p, miR-25, miR-155, miR-23a-3p, miR-519c-3p, miR-374b-5p, miR-374a, miR-31-5p, miR-3163, miR-525-5p, miR-15-5p, miR-374a-5p, miR-374b-5p, miR-218-5p, miR-141-3p and miR-200a-3p to regulate expression of their mRNA targets. The current review summarizes the role of MAGI2-AS3 in different disorders to highlight its importance in their pathophysiology.

Role of lncRNA MAGI2-AS3 in lipopolysaccharide-induced nucleus pulposus cells injury by regulating miR-374b-5p/interleukin-10 axis

BACKGROUND

Intervertebral disc degeneration (IDD) is a pathological process that occurs during the natural aging of intervertebral discs. Accumulating evidence suggests that noncoding RNAs (ncRNAs), including microRNAs and long ncRNAs (lncRNAs), participate in the pathogenesis and development of IDD. Herein, we examined the role of lncRNA MAGI2-AS3 in the pathogenic mechanism of IDD.

MATERIAL AND METHODS

To develop an IDD in vitro model, we treated human nucleus pulposus (NP) cells with lipopolysaccharide (LPS). Aberrant levels of lncRNA MAGI2-AS3, miR-374b-5p, interleukin (IL)-10 and extracellular matrix (ECM)-related proteins in NP cells were examined using reverse transcription-quantitative PCR and western blot analysis. LPS-induced NP cell injury and inflammatory response were confirmed using the MTT assay, flow cytometry, Caspase3 activity, and enzyme-linked immunosorbent assay. Dual-luciferase reporter assay and rescue experiments were performed to confirm targets between lncRNA MAGI2-AS3 and miR-374b-5p or miR-374b-5p and IL-10.

RESULTS

LPS-induced NP cells exhibited low levels of lncRNA MAGI2-AS3 and IL-10 expression, along with high miR-374b-5p expression. miR-374b-5p was a target of lncRNA MAGI2-AS3 and IL-10. LncRNA MAGI2-AS3 ameliorated injury, inflammatory response, and ECM degradation in LPS-treated NP cells by downregulating miR-374b-5p to upregulate IL-10 expression.

CONCLUSIONS

LncRNA MAGI2-AS3 increased IL-10 expression levels by sponging miR-374b-5p, which, in turn, alleviated LPS-triggered decreased NP cell proliferation and increased apoptosis, inflammatory response, and ECM degradation. Therefore, lncRNA MAGI2-AS3 may be a potential therapeutic target for IDD.

The new ceRNA crosstalk between mRNAs and miRNAs in intervertebral disc degeneration

Degeneration of the intervertebral disc has been linked to lower back pain. To date, pathophysiological mechanisms of intervertebral disc degeneration (IDD) remain unclear; it is meaningful to find effective diagnostic biomarkers and new therapeutic strategies for IDD. This study aimed to reveal the molecular mechanism of IDD pathogenesis from the multidimensional transcriptomics perspective. Here, we acquired IDD bulk omics datasets (GSE67567 and GSE167199) including mRNA, microRNA expression profiles, and single-cell RNA sequencing (GSE199866) from the public Gene Expression Omnibus (GEO) database. Through principal component analysis and Venn analysis, we found different expression patterns in the IDD transcription level and identified 156 common DEGs in both bulk datasets. GO and KEGG functional analyses showed these dysregulators were mostly enriched in the collagen-containing extracellular matrix, cartilage development, chondrocyte differentiation, and immune response pathways. We also constructed a potentially dysregulated competing endogenous RNA (ceRNA) network between mRNAs and miRNAs related to IDD based on microRNA target information and co-expression analysis of RNA profiles and identified 36 ceRNA axes including ZFP36/miR-155-5p/FOS, BTG2/hsa-miR-185-5p/SOCS3, and COL9A2/hsa-miR-664a-5p/IBA57. Finally, in integrating bulk and single-cell transcriptome data analyses, a total of three marker genes, COL2A1, PAX1, and ZFP36L2, were identified. In conclusion, the key genes and the new ceRNA crosstalk we identified in intervertebral disc degeneration may provide new targets for the treatment of IDD.

Long non-coding RNAs LINC00689 inhibits the apoptosis of human nucleus pulposus cells via miR-3127-5p/ATG7 axis-mediated autophagy

This study aimed to explore the effects of long non-coding RNAs LINC00689 (LINC00689) in human nucleus pulposus cells (NPCs). NPCs were isolated and their morphology was observed. The proliferation and apoptosis of NPCs, and the levels of LINC00689, miR-3127-5p, Bax, Bcl-2, Cleaved caspase-3, ATG5, ATG7, p62, and LC3Ⅱ/LC3I were detected. Interrelations of LINC00689, miR-3127-5p, and ATG7 were analyzed. LINC00689 was down-regulated yet miR-3127-5p was up-regulated in NPCs. LINC00689 could competitively bind with miR-3127-5p, and ATG7 was targeted by miR-3127-5p in NPCs. Overexpressed LINC00689 promoted proliferation yet inhibited apoptosis of NPCs, whereas LINC00689 silencing did the opposite. Overexpressed LINC00689 raised ATG7 level and LC3Ⅱ/LC3I value yet reduced that of p62 level, but the depletion of LINC00689 did the contrary. ATG7 silencing abolished the effects of overexpressed LINC00689 in NPCs, and likewise, up-regulation of miR-3127-5p overturned the effects of overexpressed LINC00689 in NPCs. Collectively, the up-regulation of LINC00689 inhibits the apoptosis of NPCs via miR-3127-5p/ATG7 axis-mediated autophagy.

Emerging Issues Questioning the Current Treatment Strategies for Lumbar Disc Herniation

Lumbar disc herniation is among the common phenotypes of degenerative lumbar spine diseases, significantly affecting patients' quality of life. The practice pattern is diverse. Choosing conservative measures or surgical treatments is still controversial in some areas. For those who have failed conservative treatment, surgery with or without instrumentation is recommended, causing significant expenditures and frustrating complications, that should not be ignored. In the article, we performed a literature review and summarized the evidence by subheadings to unravel the cons of surgical intervention for lumbar disc herniation. There are tetrad critical issues about surgical treatment of lumbar disc herniation, i.e., favorable natural history, insufficient evidence in a recommendation of fusion surgery for patients, metallosis, and implant removal. Firstly, accumulating evidence reveals immune privilege and auto-immunity hallmarks of human lumbar discs within the closed niche. Progenitor cells within human discs further expand the capacity with the endogenous repair. Clinical watchful follow-up studies with repeated diagnostic imaging reveal spontaneous resolution for lumbar disc herniation, even calcified tissues. Secondly, emerging evidence indicates long-term complications of lumbar fusion, such as adjacent segment disease, pseudarthrosis, implant failure, and sagittal spinal imbalance, which get increasing attention. Thirdly, systemic and local reactions (metallosis) for metal instrumentation have been noted with long-term health concerns and toxicity. Fourthly, the indications and timing for spinal implant removal have not reached a consensus. Other challenging issues include postoperative lumbar stiffness. The review provided evidence from a negative perspective for surgeons and patients who attempt to choose surgical treatment. Collectively, the emerging underlying evidence questions the benefits of traditional surgery for patients with lumbar disc herniation. Therefore, the long-term effects of surgery should be closely observed. Surgical decisions should be made prudently for each patient.

lncRNA LINC00284 promotes nucleus pulposus cell proliferation and ECM synthesis via regulation of the miR‑205‑3p/Wnt/β‑catenin axis

Intervertebral disc degeneration (IDD) is a leading cause of degenerative spinal disease. Long non-coding RNA (lncRNA) LINC00284 is overexpressed in multiple types of cancer and promotes cancer cell proliferation and inhibits apoptosis; however, its role in human IDD and nucleus pulposus (NP) remain unclear. In the present study, intervertebral disc (IVD) tissues were collected from IDD patients for detection of LINC00284 expression using reverse transcription-quantitative PCR, the binding effect between miR-205-3p and LINC00284 was validated by dual-luciferase reporter assay. miR-205-3p and small interfering RNA (siRNA) was used for LINC00240 knockdown to investigate the proliferation, apoptosis of cells in the NP cells measured by Cell Counting Kit (CCK)-8 assay and Annexin V-FITC/Propidium Iodide (PI) staining with flow cytometry receptivity. IDD animal models were constructed for in vivo study of the role LINC00284 in IDD improvement. The results showed that LINC00284 expression was upregulated in IDD tissue and IL-1β-induced NP cells. LINC00284 knockdown resulted in an increase in IL-1β-induced NP cell proliferation, a decrease in apoptosis and matrix metalloproteinase-3 expression and an increase in expression of extracellular matrix (ECM) markers aggrecan and collagen II. In vivo experiments and histomorphometric analysis confirmed the protective effect of LINC00284 knockdown in IDD. LINC00284 was also shown to be a target of microRNA (miR)-205-3p, and there was a negative correlation between LINC00284 and miR-205-3p levels in IDD tissue. Additionally, LINC00284 knockdown or miR-205-3p upregulation resulted in inhibition of Wnt/β-catenin signaling and subsequent degradation of the ECM. The present study demonstrated that LINC00284 activated the Wnt/β-catenin signaling via sponging miR-205-3p, resulting in inhibition of NP cell proliferation and ECM synthesis. These results suggested that targeting LINC00284 to rescue miR-205-3p expression may be a potential method for IDD management.

Hsa_circ_0134111 promotes intervertebral disc degeneration via sponging miR-578

Intervertebral disc degeneration (IDD) is a chronic degenerative and age-dependent process characterized by aberrant apoptosis, proliferation, synthesis, and catabolism of the extracellular matrix of the nucleus pulposus (NP) cells. Recently, studies showed that circular RNAs play important roles in the development of many diseases. However, the role of circRNAs in IDD development remains unknown. We showed that circ_0134111 level was overexpressed in IDD tissue samples as compar-ed to control tissues. The upregulation of circ_0134111 was more drastic in the moderate and severe IDD cases than in those with mild IDD. In addition, we showed that interleukin-1β and tumor necrosis factor-α exposure significantly enhanced circ_0134111 expression in NP cells. Furthermore, ectopic expression of circ_0134111 induced proliferation, pro-inflammatory cytokine secretion, and ECM degradation in the NP cells. We also showed that circ_0134111 directly interacted with microRNA (miR)-578 in NP cells where elevated expression of circ_0134111 enhanced the ADAMTS-5 and MMP-9 expression. Moreover, miR-578 expression was significantly decreased in IDD patients and the miR-578 expression was negatively correlated with circ_0134111 expression in the IDD samples. Interleukin-1β and tumor necrosis factor-α exposure significantly decreased miR-578 levels in NP cells, in which ectopic miR-578 expression inhibited cell growth, pro-inflammatory cytokine expression, and ECM degradation. Finally, we showed that circ_0134111 overexpression induced the IDD-related phenotypic changes through inhibiting miR-578. These data suggested that circ_0134111 could promote the progression of IDD through enhancing aberrant NP cell growth, inflammation, and ECM degradation partly via regulating miR-578.

LncRNA MIR155HG functions as a ceRNA of miR-223-3p to promote cell pyroptosis in human degenerative NP cells

Nucleus pulposus (NP) cell pyroptosis plays a critical role in the pathogenesis of intervertebral disk degeneration (IDD). MIR155 host gene (MIR155HG) is a long non-coding RNA with pro-inflammatory activity. However, very little is known about its role in NP cell pyroptosis. This study aimed to observe the impact of MIR155HG on cell pyroptosis and to explore the underlying mechanism in human degenerative NP cells. Our results demonstrated that MIR155HG expression was significantly increased in human degenerative NP tissue samples and showed a positive correlation with Pfirrmann score. Overexpression of MIR155HG through a lentiviral vector decreased miR-223-3p levels, up-regulated NLRP3 expression and induced cell pyroptosis in human degenerative NP cells. A ceRNA action mode was identified among MIR155HG, miR-223-3p, and NLRP3. The stimulatory effect of MIR155HG on human degenerative NP cell pyroptosis was significantly reversed by pretreatment with miR-223-3p mimic or NLRP3 siRNA. In summary, these data suggest that MIR155HG sponges miR-223-3p to promote NLRP3 expression, leading to induction of cell pyroptosis in human degenerative NP cells. Targeting MIR155HG could be a novel and promising strategy to slow down the progression of IDD.

Circular RNA hsa_circ_0001658 Inhibits Intervertebral Disc Degeneration Development by Regulating hsa-miR-181c-5p/FAS

METHODS

We obtained microarray data (GSE116726, GSE67566) from Gene Expression Omnibus database, and differential expression level of ncRNA in nucleus pulposus (NP) tissues of IDD patients was analyzed. The potential circRNA-miRNA-mRNA regulatory network was analyzed by starBase. The effect of the interaction between hsa_circ_0001658, hsa-miR-181c-5p, and FAS on the proliferation and apoptosis of human neural progenitor cells (hNPCs) was studied.

RESULTS

hsa_circ_0001658 was significantly upregulated (logFC > 2.0 and adj.P.Val < 0.01) in the NP tissues of IDD patients, and hsa-miR-181c-5p expression was downregulated (logFC < -2.0 and adj.P.Val < 0.01). Silencing of hsa-miR-181c-5p or overexpression of hsa_circ_0001658 inhibited the proliferation of hNPCs and promoted their apoptosis. hsa_circ_0001658 acted as a sponge of hsa-miR-181c-5p. hsa-miR-181c-5p downregulated the expression of Fas cell surface death receptor (FAS), promoted the proliferation, and inhibited the apoptosis of hNPCs. hsa_circ_0001658 functioned in hNPCs through targeting hsa-miR-181c-5p/FAS.

CONCLUSION

Circular RNA hsa_circ_0001658 inhibits IDD development by regulating hsa-miR-181c-5p/FAS. It is expected to be a potential target for the therapy of IDD.

LncRNA JPX regulates proliferation and apoptosis of nucleus pulposus cells by targeting the miR-18a-5p/HIF-1α/Hippo-YAP pathway

With the aggravation of global aging, the rapid rise in the obesity rate, and the increasing number of patients with intervertebral disc degeneration (IDD), the principles and mechanism of this disease remain unclear. This study explored the molecular mechanism of IDD treatment through interactions of the lncRNA-miRNA-mRNA-signaling pathways and the effects on the proliferation and apoptosis of human nucleus pulposus cells (HNPCs) cultured in vitro. Our study revealed that lncRNA JPX is expressed at low levels in HNPCs under normoxic conditions. Luciferase and RNA pull-down assays were used to verify that lncRNA JPX directly bound to miR-18a-5p and influenced HNPC proliferation and apoptosis. Subsequently, a luciferase assay confirmed the direct binding of miR-18a-5p to HIF-1α and demonstrated a negative correlation between miR-18a-5p and HIF-1α. In addition, the HIF-1α antagonist reversed the inhibition of the Hippo-YAP pathway by the miR-18a-5p inhibitor. In conclusion, overexpression of lncRNA JPX upregulated HIF-1α by inhibiting the expression of miR-18a-5p, thereby inhibiting the Hippo-YAP pathway. By inhibiting this pathway, JPX overexpression promoted the proliferation of HNPCs and decreased their apoptosis. Therefore, the lncRNA JPX is a potential new target.

Long Noncoding RNA ANPODRT Overexpression Protects Nucleus Pulposus Cells from Oxidative Stress and Apoptosis by Activating Keap1-Nrf2 Signaling

Oxidative stress and subsequent nucleus pulposus (NP) cell apoptosis are important contributors to the development of intervertebral disc degeneration (IDD). Emerging evidences show that long noncoding RNAs (lncRNAs) play a role in the pathogenesis of IDD. In this study, we investigated the role of lncRNA ANPODRT (anti-NP cell oxidative damage-related transcript) in oxidative stress and apoptosis in human NP cells. We found that ANPODRT was downregulated in degenerative NP tissues and in NP cells treated with tert-butyl hydroperoxide (TBHP, the oxidative stress inducer). ANPODRT overexpression alleviated oxidative stress and apoptosis in NP cells exposed to TBHP, while ANPODRT knockdown exerted opposing effects. Mechanistically, ANPODRT facilitated nuclear factor E2-related factor 2 (Nrf2) accumulation and nuclear translocation and activated its target genes by disrupting the kelch-like ECH-associated protein 1- (Keap1-) Nrf2 association in NP cells. Nrf2 knockdown abolished the antioxidative stress and antiapoptotic effects of ANPODRT in NP cells treated with TBHP. Collectively, our findings suggest that ANPODRT protects NP cells from oxidative stress and apoptosis, at least partially, by activating Nrf2 signaling, implying that ANPODRT may be a potential therapeutic target for IDD.

LncRNA LINC00324 is upregulated in intervertebral disk degeneration and upregulates FasL in nucleus pulposus cells

BACKGROUND

It has been reported that long intergenic non-protein-coding RNA 324 (LINC00324) promotes liver cancer by upregulating Fas ligand (FasL), which is a major player in intervertebral disk degeneration (IDD), indicating the involvement of LINC00324 in IDD. This study was carried out to investigate the interaction between LINC00324 and FasL in IDD.

METHODS

Plasma samples were collected from both IDD (n = 60) and healthy controls (n = 60). The expression of LINC00324 and FasL in plasma was determined by RT-qPCR. The interactions between LINC00324 and FasL in nucleus pulposus (NP) cells were analyzed by overexpression experiments.

RESULTS

LINC00324 and FasL were upregulated in IDD patients, and they were positively correlated. After treatment, the expression levels of FasL and LINC00324 were significantly decreased. In NP cells, overexpression of LINC00324 increased the expression of FasL at both mRNA and protein levels, while overexpression of FasL did not affect the expression of LINC00324.

CONCLUSION

LINC00324 may upregulate FasL in IDD to promote disease progression.

LncRNA NEAT1 promotes nucleus pulposus cell matrix degradation through regulating Nrf2/ARE axis

Background

This study aimed to assess the role and mechanism of lncRNA NEAT1 in intervertebral disc degeneration (IVD).

Methods

LncRNA profile (GSE56081) between IVD and healthy control was downloaded from the Gene Expression Omnibus (GEO) database and analyzes differential lncRNA expression. Expression of lncRNA NEAT1 in IVD tissue and TNF-α/IL-1β-stimulated nucleus pulposus cells were further measured by RT-PCR. The lncRNA NEAT1 overexpression plasmids (pcDNA-NEAT1) were constructed and transfected into nucleus pulposus cells. Catabolic biomarkers (MMP-3 and MMP-13), anabolic biomarkers (Col II and Aggrecan) and Nrf2 expression were further measured. To further investigate the function of Nrf2, nucleus pulposus cells were pretreated with or without 25 μM tert-Butylhydroquinone (TBHQ), a Nrf2 activator, for 18 h and subsequently cotreated with pcDNA-NEAT1.

Results

A total of 1432 lncRNAs were differentially expressed in GSE56081. Bioinformatic analysis found that these lncRNAs mainly enriched in Nrf2/ARE signaling pathway. LncRNA NEAT1 was highly expressed in IVD tissues than that of healthy control. Moreover, TNF-α/IL-1β induced a time- and dose-dependent increase in the mRNA expression of lncRNA NEAT1 in the nucleus pulposus cells. Overexpression of lncRNA NEAT1 abates promotes nucleus pulposus cells proliferation but induces matrix degradation. Meanwhile, nucleus and cytoplasm Nrf2 expression was significantly down-regulated by lncRNA NEAT1 upregulation. Nrf2 activator (TBHQ) could partially reverse the inhibitory effects of overexpression of lncRNA NEAT1 on matrix degradation.

Conclusion

Collectively, our data unveiled the lncRNA NEAT1 promotes matrix degradation by regulating Nrf2/ARE signaling pathway, suggesting a potential therapeutic for IVD in the future.

Targeted therapy for intervertebral disc degeneration: inhibiting apoptosis is a promising treatment strategy

Intervertebral disc (IVD) degeneration (IDD) is a multifactorial pathological process associated with low back pain (LBP). The pathogenesis is complicated, and the main pathological changes are IVD cell apoptosis and extracellular matrix (ECM) degradation. Apoptotic cell loss leads to ECM degradation, which plays an essential role in IDD pathogenesis. Apoptosis regulation may be a potential attractive therapeutic strategy for IDD. Previous studies have shown that IVD cell apoptosis is mainly induced by the death receptor pathway, mitochondrial pathway, and endoplasmic reticulum stress (ERS) pathway. This article mainly summarizes the factors that induce IDD and apoptosis, the relationship between the three apoptotic pathways and IDD, and potential therapeutic strategies. Preliminary animal and cell experiments show that targeting apoptotic pathway genes or drug inhibition can effectively inhibit IVD cell apoptosis and slow IDD progression. Targeted apoptotic pathway inhibition may be an effective strategy to alleviate IDD at the gene level. This manuscript provides new insights and ideas for IDD therapy.

Role of lncRNA PART1 in intervertebral disc degeneration and associated underlying mechanism

Intervertebral disc degeneration (IDD) is a chronic skeletal muscle degeneration disease. Previous studies have demonstrated that long non-coding RNAs (lncRNAs) exert significant roles in serious illnesses. Prostate androgen-regulated transcript 1 (PART1) is an identified lncRNA that has been reported to be a regulator in a number of diseases. However, the potential effects of PART1 in IDD have yet to be fully elucidated. The present study aimed to investigate the roles of lncRNA PART1 in IDD and identify a possible underlying mechanism. Human nucleus pulposus (NP) cells were first exposed to lipopolysaccharide (LPS) to construct in vitro IDD models. Reverse transcription-quantitative PCR (RT-qPCR) was performed to measure lncRNA PART1 expression levels in 10 ng/ml LPS-stimulated NP cells and normal cells (untreated cells). Dual-luciferase reporter assays were conducted to verify the possible binding sites of microRNA (miR)-190a-3p on lncRNA PART1. In addition, NP cell viability and apoptosis were measured by performing MTT and flow cytometry, respectively. Expression and secretion of inflammatory factors (TNF-α, IL-1β and IL-6) and extracellular matrix (ECM) degradation-related proteins (aggrecan and collagen type II) were measured using ELISA, RT-qPCR and western blotting. Expression levels of lncRNA PART1 in LPS-treated NP cells were found to be higher compared with those in the control groups. miR-190a-3p directly targeted lncRNA PART1. PART1 knockdown enhanced cell viability, reduced cell apoptosis, inhibited inflammatory factor secretion and promoted ECM degradation in LPS-stimulated NP cells. However, transfection with the miR-190a-3p inhibitor reversed the aforementioned PART1 knockdown-induced alterations in cell viability, apoptosis, inflammatory cytokine and ECM degradation. Collectively, these results suggest that PART1 accelerates the progression of IDD by directly targeting miR-190a-3p, which provides a novel target for IDD diagnosis and treatment.

LINC01121 induced intervertebral disc degeneration via modulating miR-150-5p/MMP16 axis

BACKGROUND

Growing evidence indicates that Long noncoding RNAs contribute to cell differentiation, invasion, metabolism, proliferation and metastasis. However, the potential role of LINC01121 in progression of intervertebral disc degeneration (IDD) remains unclear.

METHODS

LINC01121, matrix metalloprotease (MMP)-16 and miR-150-5p expression was determined by a quantitative-reverse transcriptase-polymerase chain reaction assay. Inflammatory cytokines level was measured by an enzyme-linked immunosorbent assay and cell counting kit-8 analysis was used to assess cell proliferation. MMP-16-specific binding with miR-150-5p was verified with a luciferase reporter assay.

RESULTS

We noted that interleukin (IL)-1β and tumor necrosis factor (TNF)-α treatment enhanced LINC01121 and MMP-16 expression in nucleus pulposus (NP) cells. LINC01121 was higher in IDD specimens compared to that in control specimens. Higher expression of LINC01121 was correlated with disc degeneration degree. Ectopic expression of LINC01121 enhanced cell proliferation and promoted ki-67, MMP-3 and ADAMTS5 expression and also suppressed collagen II expression in NP cells. We observed that overexpression of LINC01121 increased the secretion of three inflammatory cytokines, including IL-6, TNF-α and IL-1β. We found that ectopic expression of LINC01121 decreased the miR-150-5p level in NP cells. Luciferase reporter data confirmed that MMP-16 was one direct target of miR-150-5p. Overexpression of miR-150-5p inhibited MMP-16 level and elevated the expression of LINC01121 enhanced MMP-16 level. We also found that MMP-16 was up-regulated in IDD specimens compared to that in control specimens. Higher expression of MMP-16 was correlated with disc degeneration degree. Interestingly, MMP-16 expression was positively related to LINC01121 in IDD specimens. Finally, overexpression of LINC01121 regulated cell growth, extracellular matrix degradation and inflammatory cytokine secretion via modulating MMP-16.

CONCLUSIONS

our data suggested LINC01121 may be a new therapeutic target for IDD.