AMPK x TGF-β1

The blood FGF21 expression has been previously suggested to increase in patients developing atopic dermatitis (AD) and asthma. However, its impact on atopic march is rarely analyzed. The present work focused on investigating the role of Fibroblast Growth Factor 21(FGF21) in atopic march mice and its underlying mechanisms.

The models were induced with Diisononyl phthalate (DINP) and OVA in wild-type C57BL/6 and FGF21^-/- mice. RAW264.7 cells were induced by LPS with/without FGF21 or KLB-SiRNA for in vitro analyses.

The data indicated that there were more severe allergic reactions including IgE levels and the proportion of mast cells in the blood of FGF21^-/- mice in relative to WT model mice during the progression from AD to asthma. However, exogenous administration of FGF21 inhibited allergies. In this study, we reported that FGF21 mitigated AD-like lesions and Th1/2 or Th17/Treg cell imbalance in AD mice, and significantly decreased TSLP, IL-33, IL-4, IL-5, IL-13 and IL-17A expression on skin. During the asthma phase, FGF21 improved airway remodeling by downgrading inflammatory factors IL-4, IL-5, IL-13 and IL-17A; fibrotic markers α-SMA and Collagen I; and oxidative products MDA and ROS in wild-type model mice. Compared with WT model mice, the adverse consequences were aggravated in FGF21^-/- asthmatic mice. From the mechanistic perspective, FGF21 suppressed NF-κB/NLRP3, TGF-β1/Smad3 and JNK signaling pathways and increased Nrf2 expression in vivo and in vitro. In addition, β-Klotho knockdown attenuated the ameliorative impact of FGF21 on cellular damage. Blocking AMPKα in the LPS-treated RAW264.7 cells inhibited the reduction of FGF21 and the phosphorylation of JNK.

To conclude, FGF21 alleviated atopic march by inhibiting Th2/17 immune response, and reduced airway remodeling by regulating NF-κB/NLRP3, TGF-β1/Smad3 and AMPKα/JNK pathways. Moreover, this study provides a rationale and novel ideas for applying FGF21 in treating AD and asthma.

The hallmark of non-alcoholic fatty liver disease (NAFLD) is aberrant buildup of triglycerides (TGs) in hepatocytes. Many genes promote NAFLD development. Using bioinformatics tools, we investigated the possible effect of statins on genes involved in NAFLD progression

Protein interactions of statins and NAFLD were searched in gene-drug and gene-disease databases. A Protein-Protein interaction (PPI) network was constructed to find hub genes and Molecular Complex Detection (MCODE) of NAFLD-related genes. Shared protein targets between protein targets of statins and NAFLD-associated genes were identified. Next, targets of each statin were assayed with all modular clusters in the MCODEs related to NAFLD. Biological process and pathway enrichment analysis for shared proteins was performed.

Screening protein targets for conventional statins and curated NAFLD-related genes identified 343 protein targets and 70 genes, respectively. A Venn diagram of NAFLD-related genes and protein targets of statins showed 24 shared proteins. The biological pathways on KEGG enrichment associated with the 24 shared protein sets were evaluated and included cytokine-cytokine receptor interaction, adipocytokine, PPAR, TNF and AMPK signaling pathways. Gene Ontology analysis showed major involvement in lipid metabolic process regulation and inflammatory response. PPI network analysis of 70 protein targets indicated 13 hub genes (PPARA, IL4, CAT, LEP, SREBF1, PRKCA, CYP2E1, NFE2L2, PTEN, NR1H4, ADIPOQ, GSTP1 and TGFB1). Comparing all seven statins with the three MCODE clusterings and 13 hub genes revealed that simvastatin as the most associated statin with NAFLD.

Simvastatin has the most impact on NAFLD-related genes versus other statins.

Liver fibrosis, one of the leading causes of morbidity and mortality worldwide, lacks effective therapy. The activation of hepatic stellate cells (HSCs) is the dominant event in hepatic fibrogenesis. Luteolin-7-diglucuronide (L7DG) is the major flavonoid extracted from Perilla frutescens and Verbena officinalis. Their beneficial effects in the treatment of liver diseases were well documented. In this study we investigated the anti-fibrotic activities of L7DG and the potential mechanisms. We established TGF-β1-activated mouse primary hepatic stellate cells (pHSCs) and human HSC line LX-2 as in vitro liver fibrosis models. Co-treatment with L7DG (5, 20, 50 μM) dose-dependently decreased TGF-β1-induced expression of fibrotic markers collagen 1, α-SMA and fibronectin. In liver fibrosis mouse models induced by CCl₄ challenge alone or in combination with HFHC diet, administration of L7DG (40, 150 mg·kg^-1·d^-1, i.g., for 4 or 8 weeks) dose-dependently attenuated hepatic histopathological injury and collagen accumulation, decreased expression of fibrogenic genes. By conducting target prediction, molecular docking and enzyme activity detection, we identified L7DG as a potent inhibitor of protein tyrosine phosphatase 1B (PTP1B) with an IC₅₀ value of 2.10 µM. Further studies revealed that L7DG inhibited PTP1B activity, up-regulated AMPK phosphorylation and subsequently inhibited HSC activation. This study demonstrates that the phytochemical L7DG may be a potential therapeutic candidate for the treatment of liver fibrosis.