Emodin promotes hepatic stellate cell senescence and alleviates liver fibrosis via a nuclear receptor (Nur77)-mediated epigenetic regulation of glutaminase 1.

BACKGROUND AND PURPOSE: Senescence in hepatic stellate cells (HSCs) limits liver fibrosis. Glutaminolysis promotes HSC activation. Here, we investigated how emodin affected HSC senescence involving glutaminolysis. EXPERIMENTAL APPROACH: Senescence, glutaminolysis metabolites, Nur77 nuclear translocation, glutaminase 1 (GLS1) promoter methylation and related signalling pathways were examined in human HSC-LX2 cells using multiple cellular and molecular approaches. Fibrotic mice with shRNA-mediated knockdown of Nur77 were treated with emodin-vitamin A liposome for investigating the mechanisms in vivo. Human fibrotic liver samples were examined to verify the clinical relevance. KEY RESULTS: Emodin upregulated several key markers of senescence and inhibited glutaminolysis cascade in HSCs. Emodin promoted Nur77 nuclear translocation, and knockdown of Nur77 abolished emodin blockade of glutaminolysis and induction of HSC senescence. Mechanistically, emodin facilitated Nur77/DNMT3b interaction and increased GLS1 promoter methylation, leading to inhibited GLS1 expression and blockade of glutaminolysis. Moreover, the glutaminolysis intermediate α-ketoglutarate promoted extracellular signal-regulated kinase (ERK) phosphorylation, which in turn phosphorylated Nur77 and reduced its interaction with DNMT3b. This led to decreased GLS1 promoter methylation and increased GLS1 expression, forming an ERK/Nur77/glutaminolysis positive feedback loop. However, emodin repressed ERK phosphorylation and interrupted the feedback cascade, stimulating senescence in HSCs. Studies in mice showed that emodin-vitamin A liposome inhibited glutaminolysis and induced senescence in HSCs, and consequently alleviated liver fibrosis; but knockdown of Nur77 abrogated these beneficial effects. Similar alterations were validated in human fibrotic liver tissues. CONCLUSIONS AND IMPLICATIONS: Emodin stimulated HSC senescence through interruption of glutaminolysis. HSC-targeted delivery of emodin represented a therapeutic option for liver fibrosis.

Carboxylated nanodiamond-mediated NH2-PLGA nanoparticle-encapsulated fig polysaccharides for strongly enhanced immune responses in vitro and in vivo.

Nanodiamonds (NDs), which are safe carbon nanomaterials, have been used for the transmission of DNA, proteins and drugs. The feasibility of utilizing NDs to deliver NH2-PLGA nanoparticle-encapsulated fig polysaccharides for strongly enhanced immune responses has not been clearly studied. In this study, we aimed to use NDs as carriers to deliver NH2-PLGA nanoparticle-encapsulated fig polysaccharides for strongly enhanced immune responses. ND particles with a diameter of 5 nm were functionalized by surface carboxylation and covalently conjugated with NH2-PLGA nanoparticle-encapsulated fig polysaccharides. NDs-PLGA-FP/OVA could promote antigen uptake and lymphocyte proliferation, increase the expression levels of MHC II, CD80 and CD86, and upregulate the ratio of Th1/Th2 cells in immunized mice. NDs-PLGA-FP/OVA could also upregulate the IL-17 signalling pathway for further immunological enhancement. NDs-PLGA-FP/OVA induced increased TNF-α, IFN-γ, IL-4, and IL-6 cytokine secretion and the levels of OVA-specific antibodies (IgG). These findings demonstrate that NDs-PLGA-FP/OVA have the potential to serve as an effective vaccine delivery and adjuvant system to induce vigorous and long-term immune responses.

PEI-modified macrophage cell membrane-coated PLGA nanoparticles encapsulating Dendrobium polysaccharides as a vaccine delivery system for ovalbumin to improve immune responses.

Recently, nanoparticles have been widely used in drug and vaccine adjuvant delivery. Dendrobium devonianum Polygonatum (DP), a main biologically active ingredient isolated from Dendrobium devonianum, has been widely used in the clinic as an immunostimulant to stimulate and improve immune responses, contributing to its excellent biological activity. To increase the immune efficacy of DP, macrophage cell membrane-coated drug nanocrystals featuring homologous immune escape, targeting ability and low toxicity are in high demand. In this study, a new drug and vaccine adjuvant delivery system, PEI-MM-PLGA-DP/OVA, was designed and developed. This study aimed to report the macrophage immunomodulatory activity of PEI-modified macrophage cell membrane-coated PLGA nanoparticles encapsulating Dendrobium devonianum polysaccharides. PEI-MM-PLGA-DP/OVA could promote antigen uptake by macrophage and lymphocyte proliferation, increase the expression levels of MHC II, CD80 and CD86, and upregulate the ratio of CD4+ to CD8+ T cells in immunized mice. PEI-MM-PLGA-DP/OVA induced the highest TNF-α, IFN-γ, IL-4, and IL-6 cytokine secretion levels and the levels of OVA-specific antibodies (IgG) compared with the other groups. The above results indicated that PEI-MM-PLGA-DP/OVA had better adjuvant activity than PLGA-DP/OVA and MM-PLGA-DP/OVA.

Acupuncture combined with curcumin disrupts platelet-derived growth factor ß receptor/extracellular signal-regulated kinase signalling and stimulates extracellular matrix degradation in carbon tetrachloride-induced hepatic fibrosis in rats.

BACKGROUND: Acupuncture treatment has been increasingly used to treat chronic liver diseases. We previously reported that acupuncture combined with curcumin, a natural antifibrotic compound, could remarkably attenuate liver fibrosis in chemically intoxicated rats, but the underlying molecular mechanisms are poorly understood. The present study was aimed at investigating the effects of acupuncture combined with curcumin on platelet-derived growth factor (PDGF) signalling and extracellular matrix (ECM) regulation in the fibrotic liver. METHODS: A total of 60 Sprague-Dawley male rats were randomly divided into control, model, sham, acupuncture, curcumin and combination treatment groups. During the establishment of fibrosis using carbon tetrachloride (CCl(4)), acupuncture at LR3, LR14, BL18 and ST36 and/or curcumin treatment by mouth were performed simultaneously. After treatment, serum PDGF levels were measured. Protein and mRNA expression of key effectors in PDGF pathway and fibrinolysis in the liver was determined. RESULTS: Acupuncture combined with curcumin potently reduced serum PDGF levels and selectively disrupted the PDGF-ßR/extracellular signal-regulated kinase (ERK) cascade. Combination treatment also significantly repressed expression of connective tissue growth factor and upregulated expression of matrix metalloproteinase-9, promoting fibrinolysis in the fibrotic liver. CONCLUSIONS: The beneficial effects of acupuncture and its combination with curcumin could be attributed to the disruption of PDGF-ßR/ERK pathway and stimulated ECM degradation in the fibrotic liver. Acupuncture treatment significantly enhanced curcumin effects at the molecular level. These findings may provide molecular insights into the potential of acupuncture combined with curcumin for prevention of hepatic fibrosis.

Acupuncture combined with curcumin attenuates carbon tetrachloride-induced hepatic fibrosis in rats.

BACKGROUND: Increasingly, studies demonstrate the effectiveness of acupuncture therapy against liver fibrosis. Curcumin is a natural product with antifibrotic effects, but has poor pharmacokinetic profiles. This study aimed to evaluate whether acupuncture combined with curcumin could more potently attenuate liver fibrosis in chemical intoxicated rats. METHODS: 60 Sprague-Dawley male rats were randomly divided into control, model, sham, acupuncture, curcumin and combination therapy groups. During the establishment of fibrosis using carbon tetrachloride (CCl(4)), acupuncture at LR3, LR14, BL18 and ST36 and/or curcumin treatment by mouth were performed simultaneously. After treatment, pathological indexes and histology for hepatic injury and fibrogenesis were detected. The expression of extracellular matrix (ECM) components was also determined. RESULTS: Acupuncture combined with curcumin potently protected the liver from CCl(4)-induced injury and fibrogenesis, as indicated by reduced levels of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, hyaluronic acid, laminin and procollagen III. Combined use also led to significant liver histological improvements. Furthermore, combined use effectively inhibited ECM expression such as α-smooth muscle actin, fibronectin and α1(1) collagen. CONCLUSIONS: Acupuncture treatment could significantly enhance the antifibrotic efficacy of curcumin on CCl(4)-induced hepatic fibrosis in rats in vivo, suggesting that a combination of acupuncture with curcumin may be exploited for the prevention of hepatic fibrosis.

[Stress analysis of separators with different specifications].

OBJECTIVE: To evaluate the shape and structure of different separators affecting the mechanical behavior. METHODS: The stress of different separators was analyzed by ANSYS software. Various separators were meshed into one-dimensional solid elements and the material character parameters were inputted. The loads were added gradually. RESULTS: The stress was related to the arm of force and the point of force application. CONCLUSIONS: The force applied can be controlled by selecting different separators.