Malignant progression of liver cancer progenitors requires lysine acetyltransferase 7-acetylated and cytoplasm-translocated G protein GαS.

BACKGROUND AND AIMS: Hepatocarcinogenesis goes through HCC progenitor cells (HcPCs) to fully established HCC, and the mechanisms driving the development of HcPCs are still largely unknown. APPROACH AND RESULTS: Proteomic analysis in nonaggregated hepatocytes and aggregates containing HcPCs from a diethylnitrosamine-induced HCC mouse model was screened using a quantitative mass spectrometry-based approach to elucidate the dysregulated proteins in HcPCs. The heterotrimeric G stimulating protein α subunit (GαS) protein level was significantly increased in liver cancer progenitor HcPCs, which promotes their response to oncogenic and proinflammatory cytokine IL-6 and drives premalignant HcPCs to fully established HCC. Mechanistically, GαS was located at the membrane inside of hepatocytes and acetylated at K28 by acetyltransferase lysine acetyltransferase 7 (KAT7) under IL-6 in HcPCs, causing the acyl protein thioesterase 1-mediated depalmitoylation of GαS and its cytoplasmic translocation, which were determined by GαS K28A mimicking deacetylation or K28Q mimicking acetylation mutant mice and hepatic Kat7 knockout mouse. Then, cytoplasmic acetylated GαS associated with signal transducer and activator of transcription 3 (STAT3) to impede its interaction with suppressor of cytokine signaling 3, thus promoting in a feedforward manner STAT3 phosphorylation and the response to IL-6 in HcPCs. Clinically, GαS, especially K28-acetylated GαS, was determined to be increased in human hepatic premalignant dysplastic nodules and positively correlated with the enhanced STAT3 phosphorylation, which were in accordance with the data obtained in mouse models. CONCLUSIONS: Malignant progression of HcPCs requires increased K28-acetylated and cytoplasm-translocated GαS, causing enhanced response to IL-6 and driving premalignant HcPCs to fully established HCC, which provides mechanistic insight and a potential target for preventing hepatocarcinogenesis.

Temperature difference and systemic risk: Evidence from LASSO-VAR-DY based on China's pan-financial market.

Climate change-induced pan-financial market and the contagion of systemic financial risks are becoming important issues in the financial sector. The paper measures the temperature difference in terms of the degree and direction of deviation of the actual temperature relative to the average temperature of the same historical period. Based on the high-dimensional time-series variable LASSO-VAR-DY framework, we construct a pan-financial market volatility correlation network consisting of 112 Chinese listed companies in banking, insurance, securities, real estate, traditional energy, and new energy, use eigenvector centrality to measure the systematic risk of each firm, and then empirically test the effect of temperature difference on systematic risk under pan-financial market scenario. The results of the study show that (ⅰ) There is a significant difference among the systemic risk of financial sectors such as banking, insurance, and securities in the financial market pan-financial market scenario and the systemic risk when the financial market pan-financial market is not taken into account;(ⅱ) Higher temperature significantly exacerbates systemic financial risk, while colder temperature significantly mitigates systemic risk, but both have an asymmetric effect on systemic risk, and there is sectoral heterogeneity.(ⅲ) From the dynamic evolutionary characteristics, there are significant differences in the response of systemic financial risk to positive and negative temperature shocks;(iv) The results of the systemic risk variance decomposition indicate that the temperature change contributes more to the variance of systemic risk in the banking and securities sectors in pan-financial market;(ⅴ) The contagion source of financial systemic risk shows an obvious path of leaping and changing characteristics, and the contagion source of systemic risk (source of impact) shows the evolution law of "bank → real estate → new energy → temperature difference," which means that the temperature difference has become the contagion source of systemic financial risk. This study provides a reference for preventing and resolving systemic risks under pan-financial market scenario and provides a basis for improving the current macroprudential regulatory framework.

The moderate level of digital transformation: from the perspective of green total factor productivity.

In the context of accelerated development of the digital economy, whether enterprises can drive green total factor productivity (GTFP) through digital technology has become the key to promoting high-quality development of the economy and achieving the goal of "dual-carbon", However, the relationship between digital transformation and GTFP is still controversial in existing studies. Based on the data of 150 listed companies in China's A-share energy industry from 2011 to 2021, this study empirically analyzes the impact of digital transformation on GTFP using a fixed-effect model. The study shows an inverted U-shaped nonlinear effect of digital transformation on enterprises' GTFP, and the conclusion still holds after a series of robustness tests. Mechanism analysis shows that enterprise investment efficiency and labour allocation efficiency play a significant mediating role in the above inverted U-shaped relationship, in which the inverted U-shaped relationship between digital transformation and GTFP mainly stems from the influence of enterprise investment efficiency. Heterogeneity analysis finds that the inverted U-shaped relationship between digital transformation and GTFP of enterprises is more significant in large-scale enterprises, new energy enterprises and enterprises in central and western regions. The study's findings provide important insights for enterprises to promote digital transformation and realize the green and high-quality development of the energy industry.

Interferon-α stimulates DExH-box helicase 58 to prevent hepatocyte ferroptosis.

BACKGROUND: Liver ischemia/reperfusion (I/R) injury is usually caused by hepatic inflow occlusion during liver surgery, and is frequently observed during war wounds and trauma. Hepatocyte ferroptosis plays a critical role in liver I/R injury, however, it remains unclear whether this process is controlled or regulated by members of the DEAD/DExH-box helicase (DDX/DHX) family. METHODS: The expression of DDX/DHX family members during liver I/R injury was screened using transcriptome analysis. Hepatocyte-specific Dhx58 knockout mice were constructed, and a partial liver I/R operation was performed. Single-cell RNA sequencing (scRNA-seq) in the liver post I/R suggested enhanced ferroptosis by Dhx58hep-/-. The mRNAs and proteins associated with DExH-box helicase 58 (DHX58) were screened using RNA immunoprecipitation-sequencing (RIP-seq) and IP-mass spectrometry (IP-MS). RESULTS: Excessive production of reactive oxygen species (ROS) decreased the expression of the IFN-stimulated gene Dhx58 in hepatocytes and promoted hepatic ferroptosis, while treatment using IFN-α increased DHX58 expression and prevented ferroptosis during liver I/R injury. Mechanistically, DHX58 with RNA-binding activity constitutively associates with the mRNA of glutathione peroxidase 4 (GPX4), a central ferroptosis suppressor, and recruits the m6A reader YT521-B homology domain containing 2 (YTHDC2) to promote the translation of Gpx4 mRNA in an m6A-dependent manner, thus enhancing GPX4 protein levels and preventing hepatic ferroptosis. CONCLUSIONS: This study provides mechanistic evidence that IFN-α stimulates DHX58 to promote the translation of m6A-modified Gpx4 mRNA, suggesting the potential clinical application of IFN-α in the prevention of hepatic ferroptosis during liver I/R injury.

Mitochondrial IRG1 traps MCL-1 to induce hepatocyte apoptosis and promote carcinogenesis.

Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis remain to be fully investigated. Immunoresponsive gene 1 (IRG1) and its enzymatic metabolite itaconate are known to suppress inflammation in myeloid cells, and its expression in liver parenchymal hepatocytes is currently determined. However, the potential roles of IRG1 in hepatocarcinogenesis are still unknown. Here, using the diethylnitrosamine (DEN)-induced hepatocarcinogenesis mouse model, we found that IRG1 expression in hepatocytes was markedly induced upon DEN administration. The DEN-induced IRG1 was then determined to promote the intrinsic mitochondrial apoptosis of hepatocytes and liver damage, thus enhancing the subsequent hepatocarcinogenesis. Mechanistically, the mitochondrial IRG1 could associate and trap anti-apoptotic MCL-1 to inhibit the interaction between MCL-1 and pro-apoptotic Bim, thus promoting Bim activation and downstream Bax mitochondrial translocation, and then releasing cytochrome c and initiating apoptosis. Thus, the inducible mitochondrial IRG1 promotes hepatocyte apoptosis and the following hepatocarcinogenesis, which provides mechanistic insight and a potential target for preventing liver injury and HCC.

Digital financial and banking competition network: Evidence from China.

The rapid development of digital finance resulted in fierce competition in the banking industry. The study used Bank-corporate credit data to measure interbank competition based on social network model, and we transformed the regional digital finance index into bank-level digital finance index using each bank's registry and license information. Furthermore, we employed QAP (quadratic assignment procedure) to empirically test the effects of digital finance on the competitive structure among banks. Based on which, we verified its heterogeneity and investigated the mechanisms through which the digital finance affected the banking competition structure. The study finds that, digital finance reshapes the banking competition structure, and intensifies the inter-bank involution while increasing the evolution. The large nation-owned banks have been in central position in the banking network system, with stronger competitiveness and higher strength of digital finance development. For large banks, digital financial development has no significant impact on inter-bank co-opetition and is only more significantly correlated with banking weighted competitive networks. For small and medium-sized banks, digital finance has a significant impact on both co-opetition and competitive pressure. Meanwhile, digital finance also led to the increasing homogeneous competition. In addition, compared with large nation-owned banks, the competitiveness of small and medium-sized joint-equity commercial banks and urban commercial banks are more vulnerable to digital finance and resulting in homogenization problems. Mechanism analysis showed that (1) digital finance promotes the overall competitiveness of the banking industry by improving the inclusiveness of financial services, which expands the service scope (scale effect); (2) digital finance promotes the competition by improving the pricing ability, risk identification ability and finally the capital allocation ability of banks (Pricing effect). The above findings provide new ideas for the governance of banking competition and the realization of a new pattern of economic development.

JMJD4-demethylated RIG-I prevents hepatic steatosis and carcinogenesis.

BACKGROUND: Hepatocarcinogenesis is driven by necroinflammation or metabolic disorders, and the underlying mechanisms remain largely elusive. We previously found that retinoic acid-inducible gene-I (RIG-I), a sensor for recognizing RNA virus in innate immune cells, is mainly expressed by parenchymal hepatocytes in the liver. However, its roles in hepatocarcinogenesis are unknown, which is intensively investigated in this study. METHODS: DEN-induced necroinflammation-driven hepatocarcinogenesis and STAM NASH-hepatocarcinogenesis were carried out in hepatocyte-specific RIG-I knockout mice. The post-translational modification of RIG-I was determined by mass spectrometry, and specific antibodies against methylated lysine sites and the RIG-I lysine mutant mice were constructed to identify the functions of RIG-I methylation. RESULTS: We interestingly found that DEN-induced hepatocarcinogenesis was enhanced, while NASH-induced hepatocarcinogenesis was suppressed by hepatocyte-specific RIG-I deficiency. Further, IL-6 decreased RIG-I expression in HCC progenitor cells (HcPCs), which then viciously promoted IL-6 effector signaling and drove HcPCs to fully established HCC. RIG-I expression was increased by HFD, which then enhanced cholesterol synthesis and steatosis, and the in-turn NASH and NASH-induced hepatocarcinogenesis. Mechanistically, RIG-I was constitutively mono-methylated at K18 and K146, and demethylase JMJD4-mediated RIG-I demethylation suppressed IL-6-STAT3 signaling. The constitutive methylated RIG-I associated with AMPKα to inhibit HMGCR phosphorylation, thus promoting HMGCR enzymatic activity and cholesterol synthesis. Clinically, RIG-I was decreased in human hepatic precancerous dysplastic nodules while increased in NAFLD livers, which were in accordance with the data in mouse models. CONCLUSIONS: Decreased RIG-I in HcPCs promotes necroinflammation-induced hepatocarcinogenesis, while increased constitutive methylated RIG-I enhances steatosis and NASH-induced hepatocarcinogenesis. JMJD4-demethylated RIG-I prevents both necroinflammation and NASH-induced hepatocarcinogenesis, which provides mechanistic insight and potential target for preventing HCC.

SARS-CoV-2 Spike protein enhances ACE2 expression via facilitating Interferon effects in bronchial epithelium.

OBJECTIVE: In this study, we focused on the interaction between SARS-CoV-2 and host Type I Interferon (IFN) response, so as to identify whether IFN effects could be influenced by the products of SARS-CoV-2. METHODS: All the structural and non-structural proteins of SARS-CoV-2 were transfected and overexpressed in the bronchial epithelial cell line BEAS-2B respectively, and typical antiviral IFN-stimulated gene (ISG) ISG15 expression was detected by qRT-PCR. RNA-seq based transcriptome analysis was performed between control and Spike (S) protein-overexpressed BEAS-2B cells. The expression of ACE2 and IFN effector JAK-STAT signaling activation were detected in control and S protein-overexpressed BEAS-2B cells by qRT-PCR or/and Western blot respectively. The interaction between S protein with STAT1 and STAT2, and the association between JAK1 with downstream STAT1 and STAT2 were measured in BEAS-2B cells by co-immunoprecipitation (co-IP). RESULTS: S protein could activate IFN effects and downstream ISGs expression. By transcriptome analysis, overexpression of S protein induced a set of genes expression, including series of ISGs and the SARS-CoV-2 receptor ACE2. Mechanistically, S protein enhanced the association between the upstream JAK1 and downstream STAT1 and STAT2, so as to promote STAT1 and STAT2 phosphorylation and ACE2 expression. CONCLUSION: SARS-CoV-2 S protein enhances ACE2 expression via facilitating IFN effects, which may help its infection.

microRNA-199a-3p inhibits hepatic apoptosis and hepatocarcinogenesis by targeting PDCD4.

Hepatic apoptosis and the initiated liver inflammation play the initial roles in inflammation-induced hepatocarcinogenesis. Molecular mechanisms underlying the regulation of hepatocyte apoptosis and their roles in hepatocarcinogenesis have attracted much attention. A set of microRNAs (miRNAs) have been determined to be dysregulated in hepatocellular carcinoma (HCC) and participated in cancer progression, however, the roles of these dysregulated miRNAs in carcinogenesis are still poorly understood. We previously analyzed the dysregulated miRNAs in HCC using high-throughput sequencing, and found that miR-199a/b-3p was abundantly expressed in human normal liver while markedly decreased in HCC, which promotes HCC progression. Whether miR-199a/b-3p participates in HCC carcinogenesis is still unknown up to now. Hence, we focused on the role and mechanism of miR-199a/b-3p in hepatocarcinogenesis in this study. Hepatic miR-199a/b-3p was determined to be expressed by miR-199a-2 gene in mice, and we constructed miR-199a-2 knockout and hepatocyte-specific miR-199a-2 knockout mice. Diethylnitrosamine (DEN)-induced hepatocarcinogenesis were markedly increased by hepatocyte-specific miR-199a-3p knockout, which is mediated by the enhanced hepatocyte apoptosis and hepatic injury by DEN administration. In acetaminophen (APAP)-induced acute hepatic injury model, hepatocyte-specific miR-199a-3p knockout also aggravated hepatic apoptosis. By proteomic screening and reporter gene validation, we identified and verified that hepatic programed cell death 4 (PDCD4), which promotes apoptosis, was directly targeted by miR-199a-3p. Furthermore, we confirmed that miR-199a-3p-suppressed hepatocyte apoptosis and hepatic injury by targeting and suppressing PDCD4. Thus, hepatic miR-199a-3p inhibits hepatocyte apoptosis and hepatocarcinogenesis, and decreased miR-199a-3p in hepatocytes may aggravate hepatic injury and HCC development.

CARD10 promotes apoptosis inhibition of hepatocellular carcinoma cells by activating NF-κB pathway / 中国肿瘤生物治疗杂志

@# Objective: To investigate the expression of CARD10 in hepatocellular carcinoma (HCC) tissues, and the roles of CARD10 in HCC progression especially apoptosis inhibition. Methods: The expression of CARD10 was examined in pared non-tumor liver tissues and HCC tissues using qRT-PCR, and their correlation with HCC TNM stage was analyzed using Spearman’s rank correlation assay in SPSS 17.0. In HCC cells with CARD10 overexpression or knockdown, cytometry using Annexin-V/PI labeling was used to measure apoptosis, and Western blotting was used to determine the activation of NF-κB pathway. Results: CARD10 expression was significantly increased in HCC tissues as compared to that in pared non-tumor liver tissues (P<0.01), and the increased CARD10 in HCC was positively correlated with TNM staging (P<0.01). The apoptosis of HCC cell lines SMMC-7721 and BEL-7402 was inhibited by CARD10 overexpression while promoted by CARD10 knockdown, and the pro-survival NF-κB pathway was also enhanced by CARD 10 over-expression while suppressed by CARD10 knockdown. Conclusion: CARD10 expression is increased in HCC tissues and positively correlated with HCC progression. CARD10 inhibits HCC apoptosis by promoting the activation of NF-κB pathway. [Key words] hepatocellular carcinoma (HCC); caspase recruitment domain family member 10 (CARD10); apoptosis; NF-κB

Roles of RIG-I in tumorigenesis and progression / 中国肿瘤生物治疗杂志

@#在天然免疫应答尤其是抗病毒天然免疫应答中，维甲酸诱导基因-I（retinoic acid inducible gene I,RIG-I）是重要的胞内 病毒RNA模式识别受体，其通过结合和识别病毒来源的RNA进而活化下游RIG-I信号通路，从而激发炎症因子和I型干扰素的 表达，实现抗病毒天然免疫应答的启动。然而，新近研究表明，在肿瘤发生发展的过程中，RIG-I亦可发挥重要的调控作用。在肿 瘤进展的不同病理阶段，RIG-I可发挥抑制或促进肿瘤进展的功能。本文就RIG-I在不同肿瘤及其发生发展不同阶段所发挥的抑 癌基因或促癌基因样作用的研究进展作一综述。