HBP1 deficiency protects against stress-induced premature senescence of nucleus pulposus.

OBJECTIVE: Senescence of nucleus pulposus (NP) cells is involved in the pathological process of intervertebral disc degeneration (IVDD). HMG-box transcription factor 1 (HBP1) is a transcriptional inhibitor that prevents proliferation and regulates premature senescence of cells. The aim of this study was to confirm whether HBP1 deficiency could protect stress-induced NP cells premature senescence. PATIENTS AND METHODS: Firstly, HBP1 protein level in human degenerated intervertebral disc tissues was detected. Then, NP cells were isolated from disc samples and transfected with plasmid to upregulate HBP1expression. H2O2 and interleukin-1b (IL-1b) were used to induce NP cells premature senescence in a different manner. Thereafter, cell viability, proliferation, and apoptosis were measured, and the protein expressions of collagen II, HBP1, and p16, were determined by Western blot or immunofluorescence. Finally, the mRNA levels of aggrecan, collagen I, IL-6, Transforming Growth Factor-α (TNF-α), and matrix metalloproteinase-3 (MMP-3) were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). RESULTS: The data indicated that HBP1 was upregulated in degenerated NP tissues. HBP1 gene overexpression increased p16 expression, affected NP cell proliferation, and caused cell apoptosis. In addition, HBP1 also decreased the collagen II and aggrecan expressions but increased collagen I, IL-6, TNF-α, and MMP-3 levels. Moreover, the silencing of HBP1 markedly reversed the H2O2 and IL-1b induced NP cell senescence by reducing p16 expression, apoptotic cell population, and inflammatory response and by promoting cell proliferation. CONCLUSIONS: In summary, HBP1 accumulation contributes to the senescence of NP cells, and HBP1 deficiency protects stress-induced NP cells premature senescence.

Apelin-13/APJ system delays intervertebral disc degeneration by activating the PI3K/AKT signaling pathway.

OBJECTIVE: To study the effect of Apelin-13/APJ system on intervertebral disc degeneration and its mechanism. PATIENTS AND METHODS: This study detected the expression of APJ in human intervertebral disc tissue with varying degrees of degeneration. IL-1ß is used to stimulate the degeneration of nucleus pulposus cells. We used recombinant human Apelin-13 and Ala13 to activate and inhibit the APJ receptor, respectively. The inhibitor LY294002 was used to inhibit the PI3K/AKT signaling pathway. We studied the effects of Apelin-13/APJ system on nucleus pulposus cells and its mechanism by Western blot, RT-PCR, and so on. RESULTS: APJ is lowly expressed in the nucleus pulposus of patients with a high degree of degeneration. IL-1ß stimulates the nucleus pulposus cells and reduces the expression of APJ in nucleus pulposus cells. Recombinant human Apelin-13 reduces the degradation of nucleus pulposus extracellular matrix, promotes proliferation, and reduces the levels of apoptosis and inflammation. In addition, the Apelin-13/APJ system increases the expression of PI3K and AKT and activates the PI3K/AKT signaling pathway. CONCLUSIONS: Apelin-13/APJ system activates PI3K/AKT signaling pathway activity, reduces the degradation of nucleus pulposus extracellular matrix, promotes proliferation, and reduces the level of apoptosis and inflammation, thus delaying the degeneration of the intervertebral disc.

Long noncoding RNA PVT1 promotes metastasis via miR-484 sponging in osteosarcoma cells.

OBJECTIVE: Long noncoding RNAs (lncRNAs) are widely involved in various malignancies including osteosarcoma. In the current study, we aimed to illustrate the role of lncRNA plasmacytoma variant translocation 1 (PVT1) in osteosarcoma. PATIENTS AND METHODS: Expression of PVT1 and microRNA-486 (miR-486) in osteosarcoma tissue specimens and cell lines were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assays and in situ hybridizations (ISH) assay. Transwell migration/invasion assays were performed to determine the metastatic ability changes in osteosarcoma cells. Kaplan-Meier survival analysis was applied to analyze the overall survival (OS) of patients with osteosarcoma. Luciferase assays were used to evaluate the targeted binding effect between PVT1 and miR-486. RESULTS: We illustrated that lncRNA plasmacytoma variant translocation 1 (PVT1) was upregulated in osteosarcoma, and it was correlated with poor prognosis of patients with osteosarcoma. Furthermore, we found that PVT1, via constructed loss of function and gain of function assays, promoted osteosarcoma cells migration and invasion. Meanwhile, we demonstrated that microRNA-486 (miR-486) was involved in PVT1-induced migration and invasion. We also uncovered that miR-486 was downregulated in osteosarcoma tissue specimens and cell lines. Functionally, we showed that upregulation of miR-486 reversed the facilitative effect of PVT1 on osteosarcoma cells migration and invasion, and vice versa. Mechanically, we illustrated that PVT1 interacted with miR-486 in a reciprocal suppressed manner. Moreover, we found that miR-486 could target to PVT1 via Luciferase assay. Lastly, we proved that PVT1 promoted osteosarcoma cells migration and invasion through miR-486 sponging. CONCLUSIONS: We demonstrated that PVT1, functioning as an oncogene, promotes osteosarcoma cells metastasis via miR-486 sponging. PVT1/miR-486 axis might be a novel target in the molecular treatment of osteosarcoma.

Biosorption of Methylene Blue onto spent corncob substrate: kinetics, equilibrium and thermodynamic studies.

This study focuses on the possible use of the spent corncob substrate (SCS), an agricultural waste used after the cultivation of white rot fungus Pleurotus ostreatus, to adsorb Methylene Blue (MB) from aqueous solutions. A batch adsorption study was carried out with variable solution pH, adsorption time, temperature and initial MB concentration. It was found that MB uptake was favorable at pH ranging from 4.0 to 12.0 and the equilibrium adsorption capacity can be reached promptly within about 180 min. The biosorption data were also calculated by the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters show that the adsorption is a spontaneous and endothermic process. The study highlighted a new pathway to develop potential low-cost biosorbent for the removal of dye pollutants from wastewater.