cyclin-d1 and Intervertebral-Disc-Degeneration

To explore the effect of ginsenoside Rg1 on intervertebral disc degeneration (IVDD) in vivo and in vitro and its mechanism.. 60 rats were underwent surgery to construct rat models of IVDD and divided in the sham group, model group and gradient G-Rg1 groups (10 mg/kg/d, 20 mg/kg/d and 40 mg/kg/d).The change of histology was observed by HE staining, the water content and the expression of β-catenin in IVD were detected. Rat nucleus pulposus cells(NPCs) were isolated from IVDD rats and divided in D-NPCs group, and gradient G-Rg1 groups(20 μg/ml, 50 μg/ml and 100 μg/ml).The cell proliferation activity, cell apoptosis rate,the expression of proteins related to ECM and Wnt/β-catenin were detected respectively, Finally the agonist of Wnt/β-catenin pathway LiCl was used for reversed experiments.. In vivo, G-Rg1 treatment could improve the structural disorganization, low water content, NPCs number and aggrecan and collagenⅡ expression in IVD and down-regulate the expression of β-catenin. In vitro NPCs, G-Rg1 treatment could improve the low cell proliferation, high apoptosis rate and low expression of aggrecan and collagenⅡ in degenerative NPCs in a dose-dependent manner.G-Rg1 treatment could down-regulate the expression of proteins related to β-catenin signal and LiCl could reverse the increase of cell proliferation and ECM synthesis, decrease of apoptosis of degenerative NPCs induced by G-Rg1.. G-Rg1 could promote ECM synthesis of degenerative NPCs and inhibiting its apoptosis, improve the IVDD via inhibiting the Wnt/β-catenin pathway.

Topics: Aggrecans; Animals; Apoptosis; beta Catenin; Cell Proliferation; Collagen; Cyclin D1; Ginsenosides; Intervertebral Disc Degeneration; Male; Models, Animal; Nucleus Pulposus; Proto-Oncogene Proteins c-myc; Rats; Rats, Sprague-Dawley; Wnt Signaling Pathway

Aberrant nucleus pulposus cell proliferation is implicated in the development of intervertebral disk degeneration (IDD). Recent studies have suggested that long noncoding RNAs (lncRNAs) can modulate cell proliferation in several pathological conditions. Here, we indicate that expression of SNHG1 was upregulated in IDD tissues compared with control tissues and that higher SNHG1 expression was associated with disk degeneration grade. In addition, we show that ectopic expression of SNHG1 promoted nucleus pulposus (NP) cell proliferation and increased the PCNA and cyclin D1 expression in NP cells. Ectopic expression of SNHG1 inhibited miR-326 expression in nucleus pulposus cells and promoted CCND1 expression, which is a direct target gene of SNHG1. Moreover, we demonstrate that expression of miR-326 was downregulated in IDD tissues compared with control tissues and that lower SNHG1 expression was associated with disk degeneration grade. Expression of miR-326 was negatively associated with SNHG1 expression in disk degeneration tissues. Overexpression of miR-326 inhibited NP cell growth and inhibited PCNA and cyclin D1 expression in NP cells. Furthermore, we show that overexpression of SNHG1 promoted nucleus pulposus cell proliferation through inhibiting miR-326 expression. These data shed novel light on the role of SNHG1 in the pathogenesis of IDD.

Topics: Adult; Aged; Cell Line; Cell Proliferation; Cyclin D1; Down-Regulation; Female; Humans; Intervertebral Disc Degeneration; Male; MicroRNAs; Middle Aged; Nucleus Pulposus; Proliferating Cell Nuclear Antigen; RNA, Long Noncoding; Signal Transduction; Up-Regulation

Long noncoding RNAs (LncRNAs) are involved in the pathogenesis of intervertebral disc degeneration (IDD). However, the biological function and expression of RMRP were still unclear. In our study, we showed that RMRP expression was up-regulated in degenerated NP tissues compared to normal NP samples, and higher RMRP expression was associated with the disc degeneration grade. Further studies indicated that ectopic expression of RMRP enhanced NP cell growth and also enhanced the expression of ki-67, PCNA and cyclin D1 in the NP cell. Moreover, overexpression of RMRP promoted the expression of Type II collagen and aggrecan and suppressed the expression of MMP13 and ADAMTS4. In addition, we found that the expression of miR-206 was down-regulated in degenerated NP tissues compared to normal NP samples, and lower miR-206 expression was correlated with the disc degeneration grade. Interestingly, we indicated that miR-206 expression in NP tissues was negatively correlated with the expression of RMRP. Ectopic expression of miR-206 suppressed NP cell proliferation and suppressed the expression of Type II collagen and aggrecan and enhanced the expression of MMP13 and ADAMTS4. Furthermore, we demonstrated that overexpression of RMRP increased NP cell growth and regulated ECM expression through targeting miR-206. These results suggested that lncRNA-RMRP promoted the progression of IDD through targeting miR-206, providing an attractive new therapeutic approach for the treatment of IDD disease.

Topics: ADAMTS4 Protein; Aggrecans; Cell Proliferation; Cells, Cultured; Cyclin D1; Extracellular Matrix; Gene Expression Regulation; Humans; Intervertebral Disc Degeneration; Matrix Metalloproteinase 13; MicroRNAs; Nucleus Pulposus; RNA, Long Noncoding

The aberrant proliferation of nucleus pulposus (NP) cells has been reported to be implicated in the pathogenesis of intervertebral disc degeneration (IDD). Previous studies have demonstrated that microRNAs (miRNAs), which are a group of small noncoding RNAs, are critical regulators of cell proliferation in various pathologies. However, the role of miRNA‑96 (miR‑96) in the proliferation of NP cells remains to be determined. In the present study, reverse transcription‑quantitative polymerase chain reaction was used to investigate the expression of miR‑96 in NP tissues from patients with IDD and healthy tissues from patients with traumatic lumbar fracture as the control. A dual‑luciferase reporter assay was used to investigate whether AT‑rich interaction domain 2 (ARID2) may be a direct target gene for miR‑96. Furthermore, isolated NP cells from patients with IDD were transfected with miR‑96 mimics and ARID2‑targeting small interfering RNAs; cell proliferation, and the protein expression of Akt, phosphorylated Akt and ARID2 were examined, whereas the effects of an Akt inhibitor on NP cell proliferation were also evaluated. The present results demonstrated that miR‑96 expression was significantly upregulated in IDD samples, and the level of miR‑96 expression was positively associated with disc degeneration grade, which was evaluated by a modified Pfirrmann grading system. In addition, the current study identified ARID2 as a direct gene target of miR‑96. Furthermore, it was demonstrated that ARID2 mRNA expression was inversely correlated with the expression of miR‑96 in NP tissues. In addition, miR‑96 overexpression promoted NP cell proliferation and induced Akt phosphorylation, which led to increased cyclin D1 translation. Notably, overexpression of ARID2 or treatment with an Akt inhibitor decreased the effect of miR‑96 on NP cell proliferation. In conclusion, the results of the present study indicate that miR‑96 may promote the proliferation of human degenerated NP cells by targeting ARID2 via activation of the Akt pathway, and potentially serves as a therapeutic target for IDD.

Topics: Adolescent; Adult; Antagomirs; Base Sequence; Cell Proliferation; Cells, Cultured; Cyclin D1; Female; Humans; Intervertebral Disc Degeneration; Male; MicroRNAs; Middle Aged; Nucleus Pulposus; Phosphorylation; Proto-Oncogene Proteins c-akt; RNA Interference; RNA, Small Interfering; Sequence Alignment; Signal Transduction; Transcription Factors; Young Adult

Degeneration of the lumbar intervertebral disc (IVD) is a cause of low back pain. In osteoarthritis patients, an increase in β-catenin accumulation has been reported. However, the molecular mechanisms involved in IVD remain unclear. In the present study, we examined the relationship of Wnt/β-catenin and transforming growth factor-β (TGF-β)/bone morphogenetic protein (BMP) signals in the IVDs. We found that treatment of nucleus pulposus (NP) cells with the Wnt/β-catenin activator lithium chloride (LiCl) results in the increased expression of β-catenin mRNA and protein, and cell proliferation is decreased due to the activation of the Wnt/β-catenin signals through the suppression of c-myc and cyclin-D1. In addition, T-cell-specific transcription factor (TCF) promoter activity was found to increase the following stimulation with LiCl alone, and was further increased when BMP2 was added, in comparison to the control group. We further observed the effects of treatment with PD98059, a specific inhibitor of the mitogen-activated protein kinase pathway, on TCF promoter activity in NP cells. These effects were largely attenuated by PD98059. Moreover, when transfected IVDs were co-transfected with R-Smad expression plasmids, there was a significant decrease in TCF reporter activity. We thereafter evaluated the effects of increased Wnt/β-catenin activity on the transcriptional activity of the Smad binding element (SBE). As a result, LiCl suppressed the activity of SBE reporter activity. The present study demonstrates for the first time that there are opposing effects between the Wnt/β-catenin and TGF-β/BMP signals in IVDs, which is consistent with the Wnt/β-catenin signals contributing to the pathogenesis of IVD degeneration.

Topics: Animals; beta Catenin; Bone Morphogenetic Protein 2; Cell Line; Cell Proliferation; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Female; Flavonoids; Intervertebral Disc; Intervertebral Disc Degeneration; Lithium Chloride; Mice; Promoter Regions, Genetic; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-myc; Rats; Rats, Sprague-Dawley; RNA, Messenger; Signal Transduction; Smad Proteins, Receptor-Regulated; TCF Transcription Factors; Time Factors; Transcriptional Activation; Transfection; Transforming Growth Factor beta; Wnt Proteins; Wnt3 Protein