Intervertebral disc degeneration (IVDD) is one of the major causes of low back pain. Polydatin (PD) has been shown to exert multiple pharmacological effects on different diseases; here, we test the therapeutic potential of PD for IVDD. In in‐vitro experiments, we confirmed PD is nontoxic to nucleus pulposus cells (NPCs) under the concentration of 400 μmol/L. Furthermore, PD was able to decrease the level of senescence in TNF‐α‐treated NPCs, as indicated by β‐gal staining as well as senescence markers p53 and p16 expression. In the aspect of extracellular matrix (ECM), PD not only reduced metalloproteinase 3 (MMP‐3), metalloproteinase 13 (MMP‐13) and a disintegrin‐like and metalloproteinase thrombospondin type 1 motif 4 (ADAMTS‐4) expression, but also increased aggrecan and collagen II levels. Mitochondrion is closely related to cellular senescence and ECM homeostasis; mechanistically, we found PD may rescue TNF‐α‐induced mitochondrial dysfunction, and it may also promote Nrf2 expression and activity. Silencing Nrf2 partly abolished the protective effects of PD on mitochondrial homeostasis, senescence and ECM homeostasis in TNF‐α‐treated NPCs. Correspondingly, PD ameliorated IVDD in rat model by promoting Nrf2 activity, preserving ECM and inhibiting senescence in nucleus pulposus cells. To sum up, our study suggests that PD exerts protective effects in NPCs against IVDD and reveals the underlying mechanism of PD on Nrf2 activation in NPCs.

The aim of this study was to investigate whether the effects of miR-490 on acute lung injury (ALI) induced by sepsis in vitro and in vivo were through targeting multi-drug resistance-associated protein 4 (MRP4). MiR-490 agomir/NC agomir was injected into mice before cecal ligation and puncture (CLP). Pulmonary microvascular endothelial cells (PMVECs) were transfected with or without miR-490 agomir/NC agomir/MRP4/empty vector before lipopolysaccharide (LPS) stimulation. Histopathology, injure score, and Wet/Dry (W/D) of lung tissues were assessed. The number of neutrophils, macrophages and total cells, total protein concentration, TNF-α and IL-1β level in bronchoalveolar lavage fluid (BALF) were measured. The levels of caspase-3, Bcl-2, TNF-α, and IL-1β were measured in MPVECs. Dual-luciferase reporter assay was used to analyze the relationship between MRP4 and miR-490. When compared to the sham group, in CLP mice, the alveolar lung tissue showed significantly hyperemic, alveolar collapse, the W/D ratio was increased, and the injury index was increased. The number of neutrophils, macrophages and total cells, total protein concentration, TNF-α and IL-1β levels were significantly increased in BALF from CLP mice. The levels of TNF-α and IL-1β were significantly increased in lung tissue from CLP mice. Overexpression of miR-490 alleviated lung injury caused by CLP and inhibited inflammation in mice. The levels of TNF-α, IL-1β and caspase-3 were significantly increased, but the level of Bcl-2 was significantly decreased in MPVECs treated with LPS compared to the control group. Overexpression of miR-490 also reversed the increase of TNF-α, IL-1β, cleaved caspase-3 and Bcl-2 caused by LPS in MPVECs. Dual-luciferase reporter assay confirmed that the target gene of miR-490 was MRP4. Besides, overexpression of MRP4 upregulated TNF-α, IL-1β, and cleaved caspase-3, but downregulated the increase of Bcl-2 induced by miR-490 agomir transfection. These data suggested that miR-490 could relieve sepsis-induced acute lung injury in neonatal mice via targeting MRP4.

Background This study aimed to explore the regulatory relationship between growth arrest special 5 (GAS5) and interleukin‐1β (IL‐1β) implicated in the development of febrile seizure (FS). Method The presence of FS and the genotype of GAS5 were used as two different indicators to divide the 50 newborn babies, recruited in this study, into different groups. The potential regulatory relationship among GAS5, miR‐21, and IL‐1β was identified by measuring their expression using quantitative reverse‐transcription polymerase chain reaction and immunohistochemistry assays among different sample groups. Computational analyses and luciferase assays were also conducted to verify the interaction between GAS5, miR‐21, and IL‐1β. Result GAS5 and IL‐1β expression was upregulated in cells collected from FS patients or genotyped as INS/DEL and DEL/DEL, whereas the expression of miR‐21 was decreased in above samples, indicating a negative relationship between miR‐21 and GAS5/IL‐1β. Results of the computational analysis showed that miR‐21 directly bound to and increased the expression of GAS5, whereas the expression of IL‐1β was suppressed by miR‐21. In the presence of GAS5, the expression of miR‐21 was lowered, whereas the expression of IL‐1β was increased. Conclusion The results obtained in this study supported the conclusion that GAS5 negatively regulated the expression of miR‐21, which in turn negatively regulated the expression IL‐1β. Therefore, the overexpression of GAS5 could decrease the magnitude of FS.