The role of interleukin-20 in liver disease: Functions, mechanisms and clinical applications.

Liver disease is a severe public health concern worldwide. There is a close relationship between the liver and cytokines, and liver inflammation from a variety of causes leads to the release and activation of cytokines. The functions of cytokines are complex and variable, and are closely related to their cellular origin, target molecules and mode of action. Interleukin (IL)-20 has been studied as a pro-inflammatory cytokine that is expressed and regulated in some diseases. Furthermore, accumulating evidences has shown that IL-20 is highly expressed in clinical samples from patients with liver disease, promoting the production of pro-inflammatory molecules involved in liver disease progression, and antagonists of IL-20 can effectively inhibit liver injury and produce protective effects. This review highlights the potential of targeting IL-20 in liver diseases, elucidates the potential mechanisms of IL-20 inducing liver injury, and suggests multiple viable strategies to mitigate the pro-inflammatory response to IL-20. Genomic CRISPR/Cas9-based screens may be a feasible way to further explore the signaling pathways and regulation of IL-20 in liver diseases. Nanovector systems targeting IL-20 offer new possibilities for the treatment and prevention of liver diseases.

NUP85 alleviates lipid metabolism and inflammation by regulating PI3K/AKT signaling pathway in nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is one of the common causes of chronic liver disease in the world. The problem of NAFLD had become increasingly prominent. However, its pathogenesis is still indistinct. As we all know, NAFLD begins with the accumulation of triglyceride (TG), leading to fatty degeneration, inflammation and other liver tissues damage. Notably, structure of nucleoporin 85 (NUP85) is related to lipid metabolism and inflammation of liver diseases. In this study, the results of researches indicated that NUP85 played a critical role in NAFLD. Firstly, the expression level of NUP85 in methionine-choline-deficient (MCD)-induced mice increased distinctly, as well as the levels of fat disorder and inflammation. On the contrary, knockdown of NUP85 had the opposite effects. In vitro, AML-12 cells were stimulated with 2 mm free fatty acids (FFA) for 24 h. Results also proved that NUP85 significantly increased in model group, and increased lipid accumulation and inflammation level. Besides, NUP85 protein could interact with C-C motif chemokine receptor 2 (CCR2). Furthermore, when NUP85 protein expressed at an extremely low level, the expression level of CCR2 protein also decreased, accompanied with an inhibition of phosphorylation of phosphoinositol-3 kinase (PI3K)-protein kinase B (AKT) signaling pathway. What is more, trans isomer (ISRIB), a targeted inhibitor of NUP85, could alleviate NAFLD. In summary, our findings suggested that NUP85 functions as an important regulator in NAFLD through modulation of CCR2.

LncRNA-XIST Promotes Lung Adenocarcinoma Growth and Inhibits Ferroptosis by Regulating GPX4.

This study aimed to explore the regulatory effects and molecular mechanisms of long non-coding RNA X-inactive-specific transcript (LncRNA-XIST) in lung adenocarcinoma. si-XIST or glutathione peroxidase 4 (GPX4) plasmids were transfected in PC-9 cells to suppress LncRNA-XIST expression or over-express GPX4, respectively. The mRNA expression levels of LncRNA-XIST and GPX4 in lung adenocarcinoma tissues or cells were assessed using RT-qPCR. CCK-8 assay was performed to examine cell activity, and corresponding biochemical kits were used to measure the levels of Fe2+, reactive oxygen species (ROS), malondialdehyde (MDA) in cells. Western blot is used to examine relative protein expression of FANCD2, SLC7A11, and GPX4 in lung adenocarcinoma cells. The mRNA and protein expression levels of LncRNA-XIST in clinical tissues and cells of lung adenocarcinoma were significantly higher than those in adjacent tissues and normal cells. Functional analysis showed that knockdown of LncRNA-XIST notably weakened the viability of lung adenocarcinoma cells and promoted ferroptosis (manifested by significantly up-regulated levels of ROS, MDA, and Fe2+ and down-regulated the expression of SLC7A11 and FANCD2, P < 0.05). Further mechanism analysis revealed that knockdown of LncRNA-XIST markedly inhibited the expression of GPX4 in lung adenocarcinoma cells and that GPX4 was significantly over-expressed in clinical tissues and cells of lung adenocarcinoma. Notably, the expression of GPX4 was positively correlated with that of LncRNA-XIST. Over-expression of GPX4 remarkably promoted cell proliferation and inhibited ferroptosis in lung adenocarcinoma. Besides, the GPX4 over-expression reversed the LncRNA-XIST knockdown-induced ferroptosis and decrease in lung adenocarcinoma cell viability. LncRNA-XIST increases the activity of lung adenocarcinoma cells and inhibits ferroptosis by up-regulating GPX4. Knocking down LncRNA-XIST may be an effective treatment for lung adenocarcinoma.

SOX9 promotes the invasion and migration of lung adenocarcinoma cells by activating the RAP1 signaling pathway.

OBJECTIVE: SOX9 has been shown to be related to the metastasis of various cancers. Recently, it has been reported that SOX9 plays a regulatory role in lung adenocarcinoma (LUAD) cell metastasis, but the specific mechanism remains to be explored. Therefore, the objective of this study was to observe the effect and mechanism of SOX9 on the invasion and migration of LUAD cells. METHODS: RT-qPCR was applied to observe the expression of SOX9 and RAP1 in tumor tissues and corresponding normal lung tissues collected from LUAD patients. Co-immunoprecipitation and Pearson correlation to analyze the expression correlation of SOX9 with RAP1. To observe the role of SOX9, the invasion and migration levels of LUAD A549 cells in each group were observed by Transwell invasion assay and Scratch migration assay after knocking down or overexpressing SOX9. Besides, the expression levels of RAP1 pathway-related proteins (RAP1, RAP1GAP and RasGRP33) were observed by RT-qCPR or western blot. Subsequently, RAP1 was overexpressed and SOX9 was knocked down in A549 cells, and then the cell invasion/migration level and RAP1 pathway activity were assessed. RESULTS: The expression levels of SOX9 and RAP1 in tumor tissues and A549 cells of LUAD patients were significantly increased and positively correlated. Overexpression of SOX9 or RAP1 alone in A549 cells enhanced the invasion and migration ability of cells, as well as up-regulated the expression levels of RAP1, RAP1GAP and RasGRP33. However, knocking down SOX9 decreased cell invasion and migration levels and weakened the activity of RAP1 pathway. Notably, overexpressing RAP1 while knocking down SOX9 significantly activated RAP1 pathway and promoted cell invasion and migration. CONCLUSION: Overexpression of SOX9 in LUAD can significantly activate the RAP1 signaling pathway and promote cell invasion and migration.

P38γ modulates the lipid metabolism in non-alcoholic fatty liver disease by regulating the JAK-STAT signaling pathway.

Non-alcoholic fatty liver disease (NAFLD) is a major health problem in Western countries and has become the most common cause of chronic liver disease. Although NAFLD is closely associated with obesity, inflammation, and insulin resistance, its pathogenesis remains unclear. The disease begins with excessive accumulation of triglycerides in the liver, which in turn leads to liver cell damage, steatosis, inflammation, and so on. P38γ is one of the four isoforms of P38 mitogen-activated protein kinases (P38 MAPKs) that contributes to inflammation in different diseases. In this research, we investigated the role of P38γ in NAFLD. In vivo, a NAFLD model was established by feeding C57BL/6J mice with a methionine- and choline-deficient (MCD) diet and adeno-associated virus (AAV9-shRNA-P38γ) was injected into C57BL/6J mice by tail vein for knockdown P38γ. The results indicated that the expression level of P38γ was upregulated in MCD-fed mice. Furthermore, the downregulation of P38γ significantly attenuated liver injury and lipid accumulation in mice. In vitro, mouse hepatocytes AML-12 were treated with free fatty acid (FFA). We found that P38γ was obviously increased in FFA-treated AML-12 cells, whereas knockdown of P38γ significantly suppressed lipid accumulation in FFA-treated AML-12 cells. Furthermore, P38γ regulated the Janus Kinase-Signal transducers and activators of transcription (JAK-STAT) signaling pathway. Inhibition of P38γ can inhibit the JAK-STAT signaling pathway, thereby inhibiting lipid accumulation in FFA-treated AML-12 cells. In conclusion, our results suggest that targeting P38γ contributes to the suppression of lipid accumulation in fatty liver disease.

Deletion of p38γ attenuates ethanol consumption- and acetaminophen-induced liver injury in mice through promoting Dlg1.

Acetaminophen (APAP) is one of the major causes of drug-induced acute liver injury, and ethanol may aggravate APAP-induced liver injury. The problem of ethanol- and APAP-induced liver injury becomes increasingly prominent, but the mechanism of ethanol- and APAP-induced liver injury remains ambiguous. p38γ is one of the four isoforms of P38 mitogen activated protein kinases, that contributes to inflammation in different diseases. In this study we investigated the role of p38γ in ethanol- and APAP-induced liver injury. Liver injury was induced in male C57BL/6 J mice by giving liquid diet containing 5% ethanol (v/v) for 10 days, followed by gavage of ethanol (25% (v/v), 6 g/kg) once or injecting APAP (200 mg/kg, ip), or combined the both treatments. We showed that ethanol significantly aggravated APAP-induced liver injury in C57BL/6 J mice. Moreover, the expression level of p38γ was up-regulated in the liver of ethanol-, APAP- and ethanol+APAP-treated mice. Knockdown of p38γ markedly attenuated liver injury, inflammation, and steatosis in ethanol+APAP-treated mice. Liver sections of p38γ-knockdown mice displayed lower levels of Oil Red O stained dots and small leaky shapes. AML-12 cells were exposed to APAP (5 mM), ethanol (100 mM) or combined treatments. We showed that P38γ was markedly increased in ethanol+APAP-treated AML-12 cells, whereas knockdown of p38γ significantly inhibited inflammation, lipid accumulation and oxidative stress in ethanol+APAP-treated AML-12 cells. Furthermore, we revealed that p38γ could combine with Dlg1, a member of membrane-associated guanylate kinase family. Deletion of p38γ up-regulated the expression level of Dlg1 in ethanol+APAP-treated AML-12 cells. In summary, our results suggest that p38γ functions as an important regulator in ethanol- and APAP-induced liver injury through modulation of Dlg1.

The Therapeutic Effect of Traditional Chinese Medicine on Inflammatory Diseases Caused by Virus, Especially on Those Caused by COVID-19.

Inflammasomes are large multimolecular complexes best recognized because of their ability to control activation of caspase-1, which in turn regulates the maturation of interleukin-18 (IL-18) and interleukin-1 ß (IL-1ß). IL-1ß was originally identified as a pro-inflammatory cytokine, capable of inducing local and systemic inflammation as well as a fever response reaction in response to infection or injury. Excessive production of IL-1ß is related to inflammatory and autoimmune diseases. Both coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS) are characterized by excessive inflammatory response. For SARS, there is no correlation between viral load and worsening symptoms. However, there is no specific medicine which is available to treat the disease. As an important part of medical practice, TCM showed an obvious therapeutic effect in SARS-CoV-infected patients. In this article, we summarize the current applications of TCM in the treatment of COVID-19 patients. Herein, we also offer an insight into the underlying mechanisms of the therapeutic effects of TCM, as well as introduce new naturally occurring compounds with anti-coronavirus activity, in order to provide a new and potential drug development strategy for the treatment of COVID-19.

Emerging role of RNF2 in cancer: From bench to bedside.

RNF2 (also known as ding, Ring1B or Ring2) is a member of the Ring finger protein family, which functions as E3 ubiquitin ligase for monoubiquitination of histone H2A at lysine 119 (H2AK119ub). RNF2 gene is located at the 1q25.3 site of human chromosome and the coding region is composed of 9 exons, encoding 336 amino acids in total. Many studies have demonstrated that overexpressed RNF2 was involved in the pathological progression of multiple cancers and has an impact on their clinical features. For instance, the upregulated expression level of RNF2 is positively correlated with the occurrence and progression of hepatocellular carcinoma, melanoma, prostate cancer, breast cancer, pancreatic cancer, gastric cancer, and bladder urothelial carcinoma, as well as with the radioresistance of lung cancer and chemoresistance of ovarian cancer. This review provides an up-to-date perspective on the relationship between RNF2 and several cancers and highlights recent studies on RNF2 regulation. In particular, the relevant cellular signaling pathways and potential clinical value of RNF2 in cancers are also discussed, suggesting its potential as an epigenetic biomarker and therapeutic target for these cancers.

ZEB1 serves an oncogenic role in the tumourigenesis of HCC by promoting cell proliferation, migration, and inhibiting apoptosis via Wnt/ß-catenin signaling pathway.

Zinc finger E-box-binding homeobox 1 (ZEB1), a functional protein of zinc finger family, was aberrant expressed in many kinds of liver disease including hepatic fibrosis and Hepatitis C virus. Bioinformatics results showed that ZEB1 was abnormally expressed in HCC tissues. However, to date, the potential regulatory role and molecular mechanisms of ZEB1 are still unclear in the occurrence and development of HCC. This study demonstrated that the expression level of ZEB1 was significantly elevated both in liver tissues of HCC patients and cell lines (HepG2 and SMMC-7721 cells). Moreover, ZEB1 could promote the proliferation, migration, and invasion of HCC cells. On the downstream regulation mechanism, ZEB1 could activate the Wnt/ß-catenin signaling pathway by upregulating the protein expression levels of ß-catenin, c-Myc, and cyclin D1. Novel studies showed that miR-708 particularly targeted ZEB1 3'-UTR regions and inhibited the HCC cell proliferation, migration, and invasion. Furthermore, results of nude mice experiments of HCC model indicated that miR-708 could inhibit tumor growth and xenograft metastasis model was established to validate that miR-708 could inhibit HCC cell metastasis through tail-vein injection in vivo. Together, the study suggested that ZEB1 modulated by miR-708 might be a potential therapeutic target for HCC therapy.

MicroRNA-708 prevents ethanol-induced hepatic lipid accumulation and inflammatory reaction via direct targeting ZEB1.

Alcoholic liver disease (ALD) was a global liver disease which divided into liver inflammation, fatty liver, alcoholic hepatitis or cirrhosis. Abnormal expression levels of some microRNAs (miRNA) family members often lead to ALD and other liver diseases. MicroRNA-708 (miR-708) was known to suppress the proliferation and metastasis of hepatocellular carcinoma (HCC), but its role in the progression of ALD was not clear. In this study, the expression level of miR-708 was down-regulated in ethanol-induced L0-2 cells. ZEB1 could decrease the PPAR-α expression while increase the SREBP-1 expression. Meanwhile, the expression levels of TNF-α and IL-6 were up-regulated by ZEB1. Of note, ZEB1 aggravated the apoptotic rate of L0-2 cells induced by ethanol via inhibiting p-AKT and p-mTOR of AKT/mTOR signaling pathway. What's more, it was demonstrated that miR-708 family members particularly target ZEB1 3'-UTR regions and can down-regulate the expression level of ZEB1 in L0-2 cells. Sum up, these results indicated that miR-708 might inhibit the liver inflammation and lipid accumulation by targeting ZEB1 via regulating AKT/mTOR signaling pathway.

The Role of IL-35 in the Pathophysiological Processes of Liver Disease.

It is known that liver diseases have several characteristics of massive lipid accumulation and lipid metabolic disorder, and are divided into liver inflammation, liver fibrosis, liver cirrhosis (LC), and hepatocellular carcinoma (HCC) in patients. Interleukin (IL)-35, a new-discovered cytokine, can protect the liver from the environmental attack by increasing the ratio of Tregs (T regulatory cells) which can increase the anti-inflammatory cytokines and inhibit the proliferation of immune cellular. Interestingly, two opposite mechanisms (pro-inflammatory and anti-inflammatory) have connection with the ultimate formation of liver diseases, which suggest that IL-35 may play crucial function in the process of liver diseases through immunosuppressive regulation. Besides, some obvious advantages also imply that IL-35 can be considered as a new therapeutic target to control the progression of liver diseases, while its mechanism of function still needs further research.

ZEB1 regulates the activation of hepatic stellate cells through Wnt/ß-catenin signaling pathway.

Zinc finger E-box binding homeobox 1 (ZEB1) (previously known as TCF8), a transcriptional repressor, is a member of the zinc-finger family of proteins. Numerous studies have demonstrated that abnormal expression of ZEB1 in many types of liver disease including hepatocellular carcinoma (HCC). Liver fibrosis is the basis and central link in the progression of liver disease. Thereby, the function of ZEB1 in liver fibrosis has been investigated. The aim of the present study was to investigate the role of ZEB1 in liver fibrosis and to elucidate the mechanism. In this study, we explored the effect of ZEB1 in hepatic stellate cells (HSCs) activation and the regulatory mechanism of the Wnt/ß-catenin signaling pathway. Additionally, ZEB1 positively regulated the expression levels of α-SMA and Col.I in vivo and in vitro, which were correlated with the activated HSCs. Furthermore, overexpression of ZEB1 could inhibit HSCs apoptosis and promote IL-6 and TNF-α secretion in LX-2 cells. Conversely, ZEB1 silencing led to the promotion of cell proliferation and the reduction of IL-6 and TNF-α secretion in LX-2 cells. Mechanically, canonical Wnt/ß-catenin signaling pathway could be regulated by ZEB1. Collectively, the data suggested that ZEB1 might play a significant role in the activation of LX-2 cells, and Wnt/ß-catenin signaling pathway might participate in this progression.

Relevance function of microRNA-708 in the pathogenesis of cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally responsible for regulating >70% of human genes. MicroRNA-708 (miR-708) is encoded in the intron 1 of the Odd Oz/ten-m homolog 4 (ODZ4) gene. Numerous researches have confirmed that the abnormal expressed miR-708 is involved in the regulation of multiple types of cancer. Notably, the expression level of miR-708 was higher in lung cancer, bladder cancer (BC) and colorectal cancer (CRC) cell lines while lower in hepatocellular carcinoma (HCC), prostate cancer (PC), gastric cancer (GC) and so on. This review provides a current view on the association between miR-708 and several cancers and focuses on the recent studies of miR-708 regulation, discussing its potential as an epigenetic biomarker and therapeutic target for these cancers. In particular, the regulated mechanisms and clinical application of miR-708 in these cancers are also discussed.

ZEB2 Attenuates LPS-Induced Inflammation by the NF-κB Pathway in HK-2 Cells.

As a transcription factor, zinc finger E-box binding homeobox 2 (ZEB2) includes multiple functional domains which interact with kinds of transcriptional co-effectors. It has been reported that ZEB2 was involved in signal transduction and multiple cellular functions. However, the functional role of ZEB2 in inflammation is still obscure. The aim of the current study is to explore the function of ZEB2 in inflammation cytokine secretion and the role of the nuclear factor-κB (NF-κB) signaling pathway in lipopolysaccharide (LPS)-induced human proximal tubule cell line (HK-2) cells. Our result demonstrated that expression of ZEB2 was significantly downregulated and expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was upregulated in response to LPS. Meanwhile, knockdown of ZEB2 by transfecting siRNA increased TNF-α and IL-6 secretion. Overexpression of ZEB2 resulted in a decrease of TNF-α and IL-6 secretion in HK-2 cells. Additionally, Western blot analysis indicated that ZEB2 suppressed the activation of the NF-κB signaling pathway via downregulating the levels of phosphorylated p65 and IκBα compared with LPS stimulation. Collectively, our data demonstrated that ZEB2 attenuated LPS-induced inflammation cytokine secretion possibly through suppressing the NF-κB signaling pathway.