[Effect of regulating TGF-ß1/Smad signaling pathway on apoptosis of hepatocellular carcinoma HepG2 cells under endoplasmic reticulum stress].

Objective: To investigate the effect of TGF-ß1/Smad signaling pathway on the apoptosis of HepG2 cells under endoplasmic reticulum stress (ERS). Methods: An ERS model was established firstly. Human hepatocellular carcinoma HepG2 cells were treated with 3 µmol/L tunicamycin (TM) for 24 h to induce ERS. Cells were divided into 6 groups, each with 3 replicate holes, and the experiment was repeated 3 times. The 6 groups included untreated group, TM group (3 µmol/L TM treatment group), TM + NC group(3 µmol/L TM + si-TGF-ß1 negative control group), TM + si-TGF-ß1 group(3 µmol/L TM + si-TGF-ß1 group), TM + pEX-3 group(3 µmol/L TM + plasmid control group), and TM + TGF-ß1 pEX-3 group(3 µmol/L TM + TGF-ß1 overexpressed plasmid group). HepG2 cells were transfected with TGF-ß1 small interfering RNA (TGF-ß1 si-RNA) and TGF-ß1 overexpressed plasmids (TGF-ß1 pEX-3) by Lipofectamine. Twenty-four hours after transfection, RT-qPCR and Western blot were used to detect the expression of TGF-ß1 and p-Smad2 in HepG2 cells of each group. CCK-8 and flow cytometry were used to analyze changes in the proliferation inhibition rate and apoptosis rate of HepG2 cells in each group. Results: Compared with the untreated group, the expressions of TGF-ß1 and p-Smad2 in TM group were significantly reduced (P＜0.05). Compared with the TM group, the expressions of TGF-ß1 and p-Smad2, as well as the cell proliferation inhibition rate and apoptosis rate in TM + si-TGF-ß1 group were obviously decreased (P＜ 0.01), while the expressions of TGF-ß1 and p-Smad2, cell proliferation inhibition rate and apoptosis rate of TM + TGF-ß1 pEX-3 group were significantly increased (P＜0.01). Conclusion: The TGF-ß1/Smad signaling pathway was inhibited in hepatocellular carcinoma HepG2 cells under ERS, when this pathway was activated, the apoptosis rate of HepG2 cells under ERS was increased significantly.

Nicotinamide mononucleotide-elicited NAMPT signaling activation aggravated adjuvant-induced arthritis in rats by affecting peripheral immune cells differentiation.

Supplement of nicotinamide mononucleotide (NMN), the direct precursor of nicotinamide adenine dinucleotide (NAD+) has gained prominence due to the significant anti-aging potentials of nicotinamide phosphoribosyltransferas (NAMPT)/NAD+ signaling. Because over-expression of NAMPT is deeply implicated in inflammatory arthritis, we investigated the effects of NMN supplement on rats with adjuvant-induced arthritis (AIA). Tested rats were given oral treatment of NMN at 200 mg/kg/day for 25 days. Arthritis score and body weight were periodically recorded. Clinical outcomes were evaluated based on arthritic manifestations, ELISA analysis and histological examination. T cells subsets were analyzed by flow cytometry. Expressions of protein and mRNA were assessed by immunoblotting and PCR methods, respectively. Levels of CD172a, CD43, and NAMPT in peripheral blood mononuclear cells (PBMCs) were investigated by immunofluorescence approach. Obtained results were further validated by experiments in vitro. Generally, NMN exacerbated AIA severity in rats. It deteriorated MMP3-controlled tissues damages, and altered immune profile by increasing Th17/Treg cells ratio. The up-regulation of NAMPT in PBMCs from NMN-treated rats was confirmed by both immunofluorescence and PCR experiments, which was synchronized with significant increase in iNOS, MCP-1, IL-1ß expression. NMN-primed AIA PBMCs were potent in up-regulating MCP-1, IL-1ß, MMP3 and p-JNK expression in synovioblast. NMN stimulus barely affected Th17 cells count in in vitro cultured splenocytes, but it greatly potentiated the capability of AIA monocytes in inducing IL-17α secretion and Th17 cells differentiation in the co-cultured splenocytes. It suggested that long-term NMN supplement could exacerbate inflammatory arthritis by reshaping the immune milieu through the up-regulation of NAMPT.

[Effects of astragaloside-IV on the expression of inflammatory factor and proliferation of glomerular mesangial cells induced by angiotensin â ¡].

OBJECTIVE: To study the effects of astragaloside-IV (As-IV) on the expression of inflammatory factor and proliferation of glomerular mesangial cells (GMCs) induced by angiotensin Ⅱ(AngⅡ). METHODS: The in vitro model of diabetic nephropathy(DN) was mimic by angiotensin Ⅱ (10-6mol/L)inducing GMCs injury. Then the GMCs were treated with As-IV at different concentrations(25,50,100 µmol/L)for 48 hours. The proliferation of GMCs was detected by MTT. The level of reactive oxidative species (ROS) was measured by flow cytometry. The expression of monocyte chemoattractant protein-1(MCP-1) protein in supernatant was detected by enzyme- linked immunosorbent assay (ELISA). The expression of transforming growth factor-ß1(TGF-ß1) in GMCs was measured by Western blot. RESULTS: Compared with model group, the proliferation of GMCs was inhibited in As-IV group. As-IV decreased the level of intercellular ROS, down-regulated the secretion of MCP-1 and the expression of TGF-ß1 proteins. CONCLUSIONS: As-IV could inhibit cell proliferation and inflammatory factors expression on GMCs induced by AngⅡ.

Reactive oxygen species mediated NF-κB/p38 feedback loop implicated in proliferation inhibition of HFLS-RA cells induced by 1,7-dihydroxy-3,4-dimethoxyxanthone.

1,7-Dihydroxy-3,4-dimethoxyxanthone (XAN) is a bioactive compound isolated from Securidaca inappendiculata Hassk. and exerts the inhibitory effects on fibroblast-like synoviocytes by targeting NF-κB and p38. This study was designed to elucidate mechanisms underlying the divergent regulation on the two pathways in HFLS-RA cells by XAN. Expressions of hallmark proteins and transcription of GADD45α mRNA were determined by Western-blot and RT-qPCR methods, respectively. Fluorescence staining was employed to evaluate intracellular oxidative stress. Effects of XAN and N-acetyl-l-cysteine (NAC) on the proliferation of cells were investigated by MTT assay, and pro-apoptotic effects of XAN were assessed by Annexin V-FITC/PI method. It was found XAN blocked NF-κB signaling in HFLS-RA cells shortly after treatment. Moreover, it up-regulated both transcription and expression of GADD45α, and subsequently activated p38 pathway. As time went on, XAN significantly promoted the generation of reactive oxygen species (ROS), which accompanied with sustained up-regulation of p-p38 and increased apoptosis. 48H later, dual-effects of XAN on NF-κB and p38 were reversed. As activation of p38 and increased apoptosis induced by XAN were antagonized by NAC, they were deemed as ROS mediated effects. Furthermore, the accumulated ROS should also account for the activation of NF-κB in the late stage of treatments via interfering in p38/MSK1/NF-κB feedback. Altogether, these findings suggested XAN-induced ROS contributed great importance to the proliferation inhibition of HFLS-RA cells by mediating NF-κB/p38 feedback loop and apoptosis, which provided us a panoramic view of potential target in the therapy of RA by XAN.