[Regulation of microRNA-126 on the polarization of human macrophages stimulated by Porphyromonas gingivalis lipopolysaccharide].

Objective: To study the effect of microRNA-126 (miR-126) on the polarization of human monocyte-derived macrophages stimulated by Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS). Methods: Macrophages derived from human myeloid leukemia mononuclear cells were stimulated by Pg-LPS (5 mg/L) and by Pg-LPS (5 mg/L) after 24 h-transfection of miR-126 mimic or negative control RNA for 48 h, respectively. Real-time quantitative-PCR (qRT-PCR), enzyme-linked immunosorbent assay (ELISA) and Western blotting were conducted to detect the changes in miR-126, pro-inflammatory factor tumor necrosis factor-α (TNF-α), anti-inflammatory factors interleukin-10 (IL-10), inducible nitric oxide synthase (iNOS), arginase-1 (Arg-1) and M1 polarization-related pathways such as nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Results: Compared with non-LPS stimulation group (TNF-α: 1.000±0.020, iNOS: 1.125±0.064, miR-126: 1.004±0.113, IL-10: 1.003±0.053, Arg-1: 1.130±0.061), the mRNA levels of TNF-α (3.105±0.278) and iNOS (4.296±0.003) increased significantly (t=6.53, P=0.003; t=42.63, P<0.001, respectively), while miR-126, IL-10 and Arg-1 expressions (0.451±0.038, 0.545±0.004 and 0.253±0.017) decreased significantly (t=7.95, P=0.001; t=7.36, P=0.002; t=11.94, P<0.001, respectively) after Pg-LPS stimulated by human-derived macrophages for 48 h. The protein expression of iNOS, TNF-α, Arg-1 and IL-10 were consistent at mRNA levels. Meanwhile, the expressions of phospho-NF-κB p65 (p-p65), phospho-extracellular signal-regulated kinase (p-ERK) and phospho-p38 MAPK (p-p38) increased significantly, while the expression of Arg-1 decreased significantly. Compared with the negative controls (scramble RNA) (TNF-α: 1.141±0.197, iNOS: 1.173±0.115, IL-10: 1.032±0.138, Arg-1: 0.933±0.044), the mRNA levels of TNF-α (0.342±0.022) and iNOS (0.588±0.085) expressions significantly decreased (t=5.35, P=0.006; t=5.05, P=0.007), while IL-10 (1.786±0.221) and Arg-1 expressions (2.152±0.229) significantly increased (t=3.71, P=0.021; t=6.21, P=0.003) after Pg-LPS stimulation with miR-126 mimic transfection. The relative protein expressions of iNOS, p-p65, p-ERK and p-p38 significantly decreased (t=13.00, P<0.001; t=6.98, P=0.002; t=10.86, P<0.001; t=8.32, P=0.001), while the protein level of Arg-1 significantly increased (t=12.08, P<0.001). Conclusions: Pg-LPS could promote M1 polarization of macrophages. miR-126 might inhibit the effect of Pg-LPS on the M1 polarization of macrophages through down-regulating NF-κB and MAPK signaling pathways.

[Regulatory effect of microRNA-126 on macrophage proliferation caused by high glucose stimulation].

Objective: To explore the effects of microRNA-126 (miR-126) on the proliferation of human myeloid leukemia mononuclear cells (THP-1)-derived macrophages in high glucose environment and the regulatory role of miR-126 in periodontitis with diabetes. Methods: THP-1 cells were cultured in vitro and 5 µg/L phorbol-12-myristate-13-acetate was applied to induce THP-1 cells differentiating into macrophages for 48 h in low glucose culture medium (5.5 mmol/L). THP-1-derived macrophages were then cultured with low glucose, medium glucose (15 mmol/L) or high glucose (25 mmol/L) media respectively. The proliferation of THP-1-derived macrophages was detected by cell counting kit-8 (CCK-8) method and the expressions of miR-126 and proliferation-associated factors were detected by quantitative real time PCR (qRT-PCR). The miR-126 mimic or inhibitor was transfected into THP-1-derived macrophages for 72 h. The proliferation of cells was detected by CCK-8 method and the expressions of miR-126 or proliferation-associated factors were detected by qRT-PCR. Results: Increasing glucose concentration decreased the proliferation of THP-1-derived macrophages (day 7, A values in low, medium and high glucose groups were 0.369±0.014, 0.214±0.009 and 0.200±0.010, respectively, P<0.01) as well as the survival rate (P<0.05), promoted the expression of miR-126, B-cell lymphoma-2 (Bcl-2)-associated X protein (BAX) and caspase-3 (P<0.05), and suppressed Bcl-2, phosphoinositol-3 kinase regulatory subunit 2 (PIK3R2) expression (P<0.05). After the miR-126 mimic was transfected in cells in low glucose medium for 72 h, compared with negative control (1.005±0.118), the expression of miR-126 significantly increased (2 980.227±170.431, P<0.05), and the proliferation of THP-1 derived macrophages decreased (negative control: 1.816±0.013, mimic group: 1.310±0.048, P<0.01), the level of BAX and caspase-3 significantly increased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly decreased (P<0.05, P<0.01). After the miR-126 inhibitor was transfected in cells cultured in high glucose medium for 72 h, compared with negative control (0.723±0.133), the proliferation of inhibitor group increased (0.984±0.049, P<0.05), the level of BAX and caspase-3 significantly decreased (P<0.01, P<0.05), PIK3R2 and Bcl-2 significantly increased (P<0.01, P<0.05). Conclusions: High glucose condition can inhibit the proliferation of THP-1-derived macrophages and increase the expression of miR-126. MiR-126 can inhibit the proliferation of THP-1-derived macrophages in high glucose environment through up-regulating the expression of BAX and caspase-3 and down-regulating the expression of PIK3R2 and Bcl-2.

[Expression profile of long non-coding RNA in gingival tissues from the patients with aggressive periodontitis].

Objective: To detect and analyze the differential expression profile of long non-coding RNA (lncRNA) in aggressive periodontitis (AgP) and healthy gingival tissues, in order to explore the role of lncRNA in AgP. Methods: After the informed consents were obtained, gingival tissues from AgP patients (n=40) and healthy volunteers (n=40) were collected in Department of Periodontology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine (from Mar. 2012 to Aug. 2012) and Department of Periodontology, Hospital of Stomatology, Tianjin Medical University (from Oct. 2016 to Apr. 2017). The differential expression of lncRNA of tissues from AgP patients (n=20) and healthy volunteers (n=20) were examined via microarray assay. Bioinformatics was applied to analyze the expression data of lncRNA and correlative mRNA. Two lncRNAs (lncRNA-TNFRSF13C and lncRNA-API5) were chosen to verify the microarray results by using real time quantitative polymerase chain reaction (PCR) in the other gingival tissues. Results: Compared with the result of healthy gingival tissues, totally 8 632 lncRNAs were differentially expressed in tissues from AgP patients. From these data, 1 986 lncRNAs were significantly upregulated while 6 646 lncRNAs were downregulated, amongst which 48 lncRNAs were upregulated (>10 times) (P<0.05), 14 lncRNAs were downregulated (>10 times) (P<0.05). Furthermore, totally 5 519 correlative mRNAs were differentially expressed, amongst which 1 676 mRNAs were upregulated (≥2 times, P<0.05) and 3 843 mRNAs were downregulated≤0.5 (P<0.05). The selected lncRNA-TNFRSF13C and lncRNA-API5 were up-regulated in AgP (P<0.05), which confirmed the results of microarray. From bioinformatics, differential expression lncRNAs were in association with many signal pathways including toll-like receptor signaling pathway, cell cycle and apoptosis pathway, and tumor necrosis factor receptor superfamily pathway. Conclusions: LncRNA may be involved in the pathogenesis of AgP through various pathways, which need to be further explored.