Research progress of the regulation of orphan nuclear receptors on chronic liver diseases / 生理学报

The development of chronic liver disease can be promoted by excessive fat accumulation, dysbiosis, viral infections and persistent inflammatory responses, which can lead to liver inflammation, fibrosis and carcinogenesis. An in-depth understanding of the etiology leading to chronic liver disease and the underlying mechanisms influencing its development can help identify potential therapeutic targets for targeted treatment. Orphan nuclear receptors (ONRs) are receptors that have no corresponding endogenous ligands to bind to them. The study of these ONRs and their biological properties has facilitated the development of synthetic ligands, which are important for investigating the effective targets for the treatment of a wide range of diseases. In recent years, it has been found that ONRs are essential for maintaining normal liver function and their dysfunction can affect a variety of liver diseases. ONRs can influence pathophysiological activities such as liver lipid metabolism, inflammatory response and cancer cell proliferation by regulating hormones/transcription factors and affecting the biological clock, oxidative stress, etc. This review focuses on the regulation of ONRs, mainly including retinoid related orphan nuclear receptors (RORs), pregnane X receptor (PXR), leukocyte cell derived chemotaxin 2 (LECT2), Nur77, and hepatocyte nuclear factor 4α (HNF4α), on the development of different types of chronic liver diseases in different ways, in order to provide useful references for the therapeutic strategies of chronic liver diseases based on the regulation of ONRs.

Study on mechanism of curcumol against liver fibrosis based on autophagy and apoptosis of hepatic stellate cells / 中国中药杂志

The present study clarified the molecular mechanism of curcumol against liver fibrosis based on its effects on the autopha-gy and apoptosis of hepatic stellate cells. The hepatic stellate cells were divided into a blank control group, a transforming growth factor-β1(TGF-β1)(10 ng·mL~(-1)) group, and low-(12.5 mg·L~(-1)), medium-(25 mg·L~(-1)), and high-dose(50 mg·L~(-1)) curcumol groups. The effect of curcumol on the viability of hepatic stellate cells induced by TGF-β1 was detected by the MTT assay kit. The apo-ptosis in each group was determined by flow cytometry. Real-time fluorescence-based quantitative PCR(RT-PCR) was employed for the detection of mRNA expression of α-smooth muscle actin(α-SMA), type Ⅰ collagen(collagen Ⅰ), and type Ⅲ collagen(collagen Ⅲ). Western blot was used to detect the protein expression of p62, microtubule-associated protein 1 light chain 3(LC3), beclin1, B cell lymphoma 2(Bcl-2), and Bcl-2-associated X protein(Bax). Transmission electron microscopy(TEM) was used to observe cell morphology and autophagosome formation in each group. The autophagic flux was observed after cell infection with adenovirus under double fluorescence labeling. The cell viability assay revealed that compared with the TGF-β1 group, the curcumol groups showed significantly decreased cell viability. The apoptosis assay showed that the apoptosis rates of the curcumol groups were significantly higher than that of the TGF-β1 group. RT-PCR indicated that the mRNA expression of α-SMA, collagenⅠ, and collagen Ⅲ in the curcumol groups was significantly lower than that of the TGF-β1 group. Western blot showed that the expression of p62, LC3, beclin1, Bcl-2, and Bax in the curcumol groups was significantly different from that in the TGF-β1 group. As demonstrated by TEM, compared with the TGF-β1 group, the curcumol groups showed significantly increased autophagosomes. The detection of autophagic flow by the adenovirus under double fluorescence labeling showed that autolysosomes in the curcumol groups were significantly increased compared with those in the TGF-β1 group. Curcumol can induce the autophagy and apoptosis of hepatic stellate cells, which may be one of its anti-liver fibrosis mechanisms.

Research progress on role of traditional Chinese medicine in hepatic fibrosis based on miRNA-mediated activation of NLRP3 inflammasome / 中国中药杂志

In recent years, liver fibrosis has become a hotspot in the field of liver diseases. MicroRNA(miRNA)-mediated Nod-like receptor pyrin domain containing 3(NLRP3) inflammasome activation is pivotal in the pathogenesis of liver fibrosis. The present study mainly discussed the role of miRNA-mediated NLRP3 inflammasome activation in the pathogenesis of liver fibrosis. Different miRNA molecules regulated liver fibrosis by mediating NLRP3 inflammasome activation, including miRNA-350-3 p(miR-350-3 p)/interleukin-6(IL-6)-mediated signal transducer and activator of transcription 3(STAT3)/c-myc signaling pathway, miR-148 a-induced autophagy and apoptosis of hepatic stellate cells via hedgehog signaling pathway, miR-155-mediated NLRP3 inflammasome by the negative feedback of the suppressor of cytokine signaling-1(SOCS-1), miR-181 a-mediated downstream NLRP3 inflammatory pathway activation through mitogen-activated protein kinase kinase(MEK)/extracellular signal-regulated kinase(ERK)/nuclear transcription factor κB(NF-κB) inflammatory pathway, miR-21-promoted expression of NF-κB and NLRP3 of RAW264.7 cells in mice by inhibiting tumor necrosis factor-α inducible protein 3(A20), and miR-20 b-promoted expression of IL-1β and IL-18 by activating NLRP3 signaling pathway. Additionally, the anti-liver fibrosis mechanism of different active components in Chinese medicines(such as Curcumae Rhizoma, Glycyrrhizae Radix et Rhizoma, Aurantii Fructus, Polygoni Cuspidati Rhizoma et Radix, Moutan Cortex, Paeoniae Radix Alba, Epimedii Folium, and Cinnamomi Cortex) was also explored based on the anti-liver fibrosis effect of miRNA-mediated NLRP3 inflammasome activation.

Effect of microRNA-125b on proliferation, apoptosis and collagen expression of hepatic stellate cells / 中国药理学通报

Aim To investigate the effect of miR-125b on HSC proliferation, apoptosis and collagen expression. Methods HSCs were transfected with miR- 125b mimics and inhibitors, and then molecular biology methods were used to detect the expression of Collagen I and HI in HSCs; MIT method was employed to detect HSC proliferation, and flow cytometry to detect HSC apoptotic rate. Results Molecular biological testing found that miR-125b mimics inhibited the expression of Collagen I and HI, and miR-125b inhibitors promoted the expression of Collagen I and HI mRNA; miR-125b mimics inhibited the proliferation of HSC, and miR-125b inhibitors promoted HSC proliferation; miR-125b mimics promoted HSC cell apoptosis, miR- 125b inhibitor inhibited HSC apoptosis, the above experimental results were statistically significant compared with its negative control group ( P < 0. 05 ). Conclusions miR-125b has anti-liver fibrosis effects, which may be related to the regulation of the phenotype of hepatic stellate cells.

Effect of curcumin against capillarization of hepatic sinusoids and its mechanism / 中国组织工程研究

BACKGROUND: Capillarization of hepatic sinusoids is an inevitable part in liver fibrosis and cirrhosis, and is a characteristic lesion inducing portal hypertension. However, curcumin effects on the capillarization of hepatic sinusoids and the underlying mechanism remain unclear. OBJECTIVE: To observe the effect of curcumin (a natural polyphenolic compound derived from the rhizome of Curcuma longa)on the microstructure and secretion of hepatic sinusoidal endothelial cells(HSECs),and to further explore its intervention on sinusoidal capillarization and pharmacological action mechanism of anti-liver fibrosis and target sites. METHODS: The rat HSECs were cultured and divided into seven groups: blank control group received no intervention and cells in the other groups were activated by leptin, followed by treatment with nothing (model group), high-, medium- and low-dose of curcumin, colchicine and salvia miltiorrhiza phenolic acid B, respectively, for 48 hours. RESULTS AND CONCLUSION: Under scanning and transmission electron microscopes, with the increasing activation of leptin, the number of fenestrae in HSECs was increased and the aperture was decreased. Curcumin could increase and enlarge narrowed or disappeared fenestrae caused by leptin, attenuated the thickness and scope of extracellular basement membrane, and reduced the degree of capillarization of hepatic sinusoids in a dose-dependent manner. Real-time PCR and ELISA results showed that after activation of leptin, mRNA and protein expression levels of endothelin-1 and vascular endothelial growth factor in HSECs were significantly increased compared with the blank control group (P < 0.05), while the expressions showed a significant decrease after treatment with curcumin in a dose-dependent manner (P < 0.05). There was also a gradient reduction in the protein expression of endothelin-1 and vascular endothelial growth factor in HSECs treated with curcumin. Moreover, all above mRNA and protein expression levels in the high-dose curcumin group were significantly lower than those in the colchicine and salvia miltiorrhiza phenolic acid B groups. In summary, curcumin can significantly alleviate the sinusoidal capillarization, and thus delay the development of liver fibrosis, probably by down-regulating the expression levels of endothelin-1 and vascular endothelial growth factor.