Liquiritin reduces lipopolysaccharide-aroused HaCaT cell inflammation damage via regulation of microRNA-31/MyD88.

BACKGROUND: Pressure ulcers are a common issue for people who have limited mobility. This study tested the impact of liquiritin on human keratinocyte HaCaT cell inflammatory damage aroused by lipopolysaccharide (LPS). METHODS: HaCaT cells were underwent LPS and/or liquiritin incubation. Cell viability, apoptosis and inflammatory molecules interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and cyclooxygenase-2 (Cox-2) expressions, along with nuclear factor kappa B (NF-κB) and c-Jun N-terminal kinase (JNK) pathways activities were tested by MTT assay, Guava Nexin assay, ELISA and western blotting, respectively. qRT-PCR was done for measuring microRNA-31 (miR-31) expression. miR-31 inhibitor was transfected to silence miR-31. Animal pressure ulcers was established on the dorsal skin of adult rats. The effects of liquiritin on wound healing were analyzed by measuring wound closure rates. RESULTS: LPS aroused HaCaT cell inflammatory damage, as evidenced by the decrease of cell viability, increase of cell apoptosis and enhanced expressions of IL-6, TNF-α and Cox-2. Liquiritin protected HaCaT cells against LPS-aroused inflammatory damage through increasing cell viability, decreasing cell apoptosis, and reducing IL-6, TNF-α and Cox-2 expressions. Liquiritin attenuated the LPS-aroused NF-κB and JNK pathways activation in HaCaT cells. Rat pressure ulcers model also confirmed that liquiritin promoted wound healing. In mechanism, miR-31 expression was boosted by liquiritin in HaCaT cells. Silencing miR-31 weakened the impacts of liquiritin on LPS-irritated HaCaT cells. Myeloid differentiation factor 88 (MyD88) was a target of miR-31 in HaCaT cells. CONCLUSION: This research affirmed the beneficial impact of liquiritin on pressure ulcers. Liquiritin reduced LPS-aroused HaCaT cell inflammatory damage might be implemented via raising miR-31 expression, lowering MyD88 expression, and repressing NF-κB and JNK pathways.

LRG1 modulates invasion and migration of glioma cell lines through TGF-ß signaling pathway.

Studies have shown that the abnormal expression of leucine-rich α2 glycoprotein 1 (LRG1) is associated with multiple malignancies, yet its role in glioma pathology remains to be elucidated. In this study, we investigated the role of LRG1 in regulating proliferation, migration and invasion of glioma cells by establishing glioma cell strains with constitutively silenced or elevated LRG1 expression. LRG1 overexpression and silenced cell lines demonstrated modulation of glioma cellular proliferation, migration and invasion through MTT, cell scratching and Transwell assays. Furthermore, overexpression of LRG1 led to augmented activation of transforming growth factor-ß (TGF-ß) signaling pathway as well as downregulation of E-cadherin and resultant enhanced invasiveness, which was reversed by TGF-ß signaling pathway inhibitor SB431542. In summary, our findings suggest that LRG1 promotes invasion and migration of glioma cells through TGF-ß signaling pathway.

Stable knockdown of LRG1 by RNA interference inhibits growth and promotes apoptosis of glioblastoma cells in vitro and in vivo.

Leucine-rich α2 glycoprotein 1 (LRG1) has been shown to be aberrantly expressed in multiple human malignancies. However, the biological functions of LRG1 in human glioblastoma remain unknown. Here, we report for the first time the role of LRG1 in glioblastoma development based on the preliminary in vitro and in vivo data. We first confirmed the expression of LRG1 in human glioblastoma cell lines. Next, to investigate the role of LRG1 in the tumorigenesis and development of glioblastoma, a short hairpin RNA (shRNA) construct targeting LRG1 mRNA was transfected into U251 glioblastoma cells to generate a cell line with stably silenced LRG1 expression. The results showed that silencing of LRG1 significantly inhibited cell proliferation, induced cell cycle arrest at G0/G1 phase, and enhanced apoptosis in U251 cells in vitro. Consistently, LRG1 silencing resulted in the downregulation of key cell cycle factors including cyclin D1, B, and E and apoptotic gene Bcl-2 while elevated the levels of pro-apoptotic Bax and cleaved caspase-3, as determined by Western blot analysis. We further demonstrate that the silencing of LRG1 expression effectively reduced the tumorigenicity of U251 cells, delayed tumor formation, and promoted apoptosis in a xenograft tumor model in vivo. In conclusion, silencing the expression of LRG1 suppresses the growth of glioblastoma U251 cells in vitro and in vivo, suggesting that LRG1 may play a critical role in glioblastoma development, and it may have potential clinical implications in glioblastoma therapy.