I_κB kinase-beta inhibitor attenuates hepatic fibrosis in mice

AIM: To investigate the anti-fibrosis effect of IκB kinase-beta inhibitor (IKK2 inhibitor IMD0354) in liver fibrosis. METHODS: Twenty male C57BL6 mice were divided into four groups. Five high-fat fed mice were injected with lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally and five high-fat fed mice were without LPS injection to build models of liver injury, and the intervention group (five mice) was injected intraperitoneally with IKK2 inhibitor (IMD 30 mg/kg for 14 d), while the remaining five mice received a normal diet as controls. Hepatic function, pathological evaluation and liver interleukin-6 (IL-6) expression were examined. Western blotting and real-time polymerase chain reaction were used to detect the expressions of nuclear factor-κB (NF-κB), alpha-smooth muscle actin (α-SMA), tumor growth factor-beta1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), typeⅠand type Ⅲ collagen proteins and mRNA. RESULTS: A mouse model of liver injury was successfully established, and IMD decreased nuclear transloca-tion of NF-κB p65 in liver cells. In the IMD-treated group, the levels of alanine aminotransferase (103 ± 9.77 μ/L vs 62.4 ± 7.90 μ/L, P < 0.05) and aminotransferase (295.8 ± 38.56 μ/L vs 212 ± 25.10 μ/L, P < 0.05) were significantly decreased when compared with the model groups. The histological changes were significantly ameliorated. After treatment, the expressions of IL-6 (681 ± 45.96 vs 77 ± 7.79, P < 0.05), TGF-β1 (Western blotting 5.65% ± 0.017% vs 2.73% ± 0.005%, P < 0.05), TNF-α (11.58% ± 0.0063% vs 8.86% ± 0.0050%, P < 0.05), typeⅠcollagen (4.49% ± 0.014% vs 1.90% ± 0.0006%, P < 0.05) and type Ⅲ collagen (3.46% ± 0.008% vs 2.29% ± 0.0035%, P < 0.05) as well as α-SMA (6.19 ± 0.0036 μ/L vs 2.16 ± 0.0023 μ/L, P < 0.05) protein and mRNA were downregulated in the IMD group compared to the fibrosis control groups (P < 0.05). CONCLUSION: IKK2 inhibitor IMD markedly improved non-alcoholic fatty liver disease in mice by lowering NF-κB activation, which could become a remedial target for liver fibrosis.

Interaction between insulin-like growth factor binding protein-related protein 1 and transforming growth factor beta 1 in primary hepatic stellate cells

BACKGROUND: We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGF beta 1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGF beta 1 in primary hepatic stellate cells (HSCs). METHODS: We overexpressed TGF beta 1 or IGFBPrP1 and inhibited TGF beta 1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of a-smooth muscle actin (alpha-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3). RESULTS: We found that the adenovirus vector encoding the TGF beta 1 gene (AdTGF beta 1) induced IGFBPrP1 expression while that of alpha-SMA, collagen I, fibronectin, and TGF beta 1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGF beta 1, alpha-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGF beta 1 expression reduced the IGFBPrP1-stimulated expression of alpha-SMA, collagen I, fibronectin, and p-Smad2/3. CONCLUSIONS: These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGF beta 1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGF beta 1-depedent manner, and may act as an upstream regulatory factor of TGF beta 1 in the Smad pathway.

Low-power laser irradiation inhibits arecoline-induced fibrosis:an in vitro study

Oral submucous fibrosis （OSF） is a potentially malignant disorder that is characterized by a progressive fibrosis in the oral submucosa. Arecoline, an alkaloid compound of the areca nut, is reported to be a major aetiological factor in the development of OSF. Low-power laser irradiation （LPLI） has been reported to be beneficial in fibrosis prevention in different damaged organs. The aim of this study was to investigate the potential therapeutic effects of LPLI on arecoline-induced fibrosis. Arecoline- stimulated human gingival fibroblasts （HGFs） were treated with or without LPLI. The expression levels of the fibrotic marker genes alpha-smooth muscle actin （a-SMA） and connective tissue growth factor （CTGF/CCN2） were analysed by quantitative real- time reverse transcription polymerase chain reaction （RT-PCR） and western blots. In addition, the transcriptional activity of CCN2 was further determined by a reporter assay. The results indicated that arecoline increased the messenger RNA and protein expression of CCN2 and a-SMA in HGF. Interestingly, both LPLI and forskolin, an adenylyl cyclase activator, reduced the expression of arecoline-mediated fibrotic marker genes and inhibited the transcriptional activity of CCN2. Moreover, pretreatment with SQ22536, an adenylyl cyclase inhibitor, blocked LPLI＇s inhibition of the expression of arecoline-mediated fibrotic marker genes. Our data suggest that LPLI may inhibit the expression of arecoline-mediated fibrotic marker genes via the cAMP signalling pathway.

Integrative omics analysis identifies macrophage migration inhibitory factor signaling pathways underlying human hepatic fibrogenesis and fibrosis

The genetic basis underlying liver fibrosis remains largely unknown.We conducted a study to identify genetic alleles and underlying pathways associated with hepatic fibrogenesis and fibrosis at the genome-wide level in 121 human livers.By accepting a liberal significance level of P<1e-4,we identified 73 and 71 candidate loci respectively affecting the variability in alpha-smooth muscle actin(a-SMA)levels(fibrogenesis)and total collagen content(fibrosis).The top genetic loci associated with the two markers were BAZA1 and NOL10 for a-SMA expression and FAM46A for total collagen content(P<1e-6).We further investigated the relationship between the candidate loci and the nearby gene transcription levels(cis-expression quantitative trait loci)in the same liver samples.We found that 44 candidate loci for a-SMA expression and 44 for total collagen content were also associated with the transcription of the nearby genes(P<0.05).Pathway analyses of these genes indicated that macrophage migration inhibitory factor(MIF)related pathway is significantly associated with fibrogenesis and fibrosis,though different genes were enriched for each marker.The association between the single nucleotide polymorphisms,MIF and a-SMA showed that decreased MIF expression is correlated with increased a-SMA expression,suggesting that variations in MIF locus might affect the susceptibility of fibrogenesis through controlling MIF gene expression.In summary,our study identified candidate alleles and pathways underlying both fibrogenesis and fibrosis in human livers.Our bioinformatics analyses suggested MIF pathway as a strong candidate involved in liver fibrosis,thus further investigation for the role of the MIF pathway in liver fibrosis is warranted.The study was reviewed and approved by the Institutional Review Board(IRB)of Wayne State University(approval No.201842)on May 17,2018.