Background/Aims: Inflammation is implicated in the pathogenesis of diabetic nephropathy (DN). This study examined the role of Toll-like receptor 2 (TLR2) in the progression of renal injury in a model of rat DN. Methods: DN was induced by intravenous injection of streptozotocin and rats were sacrificed at week 2, 4 and 8. Functional and pathologic markers, inflammatory infiltration, expression of TLR2, MCP-1, MyD88, HSP70, HMGB1 and activation of NF-ĸB were assessed. The effects of glucose on the expression of TLR2 by renal tubular epithelial cells were also examined in vitro. Results: The expression of TLR2 mRNA and protein level was significantly upregulated in the kidneys of diabetic rats (p < 0.01), which was associated with increased renal expression of MyD88 and MCP-1, activation of NF-ĸB and infiltration of macrophages. The expression of HSP70 and HMGB1, endogenous ligands of TLRs, was also significantly upregulated in the kidneys of diabetic rats. In human renal biopsy of DN, there was prominent expression of TLR2 in both the glomeruli and tubulointerstitium. In vitro study showed that high glucose induced the expression of TLR2 mRNA by NRK-52E cells (p < 0.01). Conclusions: Enhanced renal expression of TLR2 is associated with inflammatory infiltration in DN.
BackgroundThe acquisition of drug resistance has been considered as a main obstacle for cancer chemotherapy. Tumor protein 53 target gene 1 (TP53TG1), a p53-induced lncRNA, plays a vital role in the progression of human cancers. However, little is known about the detailed function and molecular mechanism of TP53TG1 in cisplatin resistance of NSCLC.MethodsqRT-PCR analysis was used to detect the expression of TP53TG1, miR-18a and PTEN mRNA in NSCLC tissues and cells. Western blot analysis was performed to determine the protein level of PTEN and cleaved caspase-3. Cell viability and IC50 value were measured by MTT assay. Cell apoptosis was confirmed by flow cytometry assay. Subcellular fractionation assay was used to identify the subcellular location of TP53TG1. Dual-luciferase reporter assay, RNA pull down assay and RNA immunoprecipitation assay were carried out to verify the interaction between TP53TG1 and miR-18a. Xenografts in nude mice were established to verify the effect of TP53TG1 on cisplatin sensitivity of NSCLC cells in vivo.ResultsTP53TG1 level was downregulated in NSCLC tissues and cell lines. Upregulated TP53TG1 enhanced cisplatin sensitivity and apoptosis of A549/DDP cells, while TP53TG1 depletion inhibited cisplatin sensitivity and apoptosis of A549 cells. TP53TG1 suppressed miR-18a expression in A549 cells. Moreover, TP53TG1-mediated enhancement effect on cisplatin sensitivity was abated following the restoration of miR-18a expression in A549/DDP cells, while si-TP53TG1-induced decrease of cisplatin sensitivity and apoptosis was counteracted by miR-18a inhibitor in A549 cells. Furthermore, TP53TG1 promoted PTEN expression via inhibiting miR-18a. Finally, TP53TG1 sensitized NSCLC cells to cisplatin in vivo.ConclusionTP53TG1 increased the sensitivity of NSCLC cells to cisplatin by modulating miR-18a/PTEN axis, elucidating a novel approach to boost the effectiveness of chemotherapy for NSCLC.Electronic supplementary materialThe online version of this article (10.1186/s13578-018-0221-7) contains supplementary material, which is available to authorized users.
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