摘要：BackgroundDysfunctional p53 signaling is one of the major causes of hepatocellular carcinoma (HCC) tumorigenesis and development, but the mechanisms underlying p53 inactivation in HCC have not been fully clarified. The role of Krüppel-associated box (KRAB)-type zinc-finger protein ZNF498 in tumorigenesis and the underlying mechanisms are poorly understood.MethodsClinical HCC samples were used to assess the association of ZNF498 expression with clinicopathological characteristics and patient outcomes. A mouse model in which HCC was induced by diethylnitrosamine (DEN) was used to explore the role of ZNF498 in HCC initiation and progression. ZNF498 overexpression and knockdown HCC cell lines were employed to examine the effects of ZNF498 on cellular proliferation, apoptosis, ferroptosis and tumor growth. Western blotting, immunoprecipitation, qPCR, luciferase assays and flow cytometry were also conducted to determine the underlying mechanisms related to ZNF498 function. ResultsZNF498 was found to be highly expressed in HCC, and increased ZNF498 expression was positively correlated with advanced pathological grade and poor survival in HCC patients. Furthermore, ZNF498 promoted DEN-induced hepatocarcinogenesis and progression in mice. Mechanistically, ZNF498 directly interacted with p53 and suppressed p53 transcriptional activation by inhibiting p53 Ser46 phosphorylation. ZNF498 competed with p53INP1 for p53 binding and suppressed PKCδ- and p53INP1-mediated p53 Ser46 phosphorylation. In addition, functional assays revealed that ZNF498 promoted liver cancer cell growth in vivo and in vitro in a p53-dependent manner. Moreover, ZNF498 inhibited p53-mediated apoptosis and ferroptosis by attenuating p53 Ser46 phosphorylation.ConclusionsOur results strongly suggest that ZNF498 suppresses apoptosis and ferroptosis by attenuating p53 Ser46 phosphorylation in hepatocellular carcinogenesis, revealing a novel ZNF498-PKCδ-p53INP1-p53 axis in HCC cells that would enrich the non-mutation p53-inactivating mechanisms in HCC.

摘要：Autophagy is a highly conserved programmed degradation process that regulates a variety of physiological and pathological activities in health, aging, and disease. To identify additional factors that modulate autophagy, we utilized serum-free starvation or Torin1 to induce autophagy in HeLa cells for unbiased mRNA-sequencing analysis and identified SNAI2, a crucial player in epithelial-to-mesenchymal transition and cancer progression, as a regulator of autophagy. Mechanistically, SNAI2 promotes autophagy by physically interacting with FOXO3 and enhancing FOXO3 binding affinity to its response elements in autophagy-related genes. Intriguingly, binding to the DNA targets appears necessary and sufficient for FOXO3 to antagonize its CRM1-dependent nuclear export, illustrating a critical role of DNA in regulating protein nuclear localization. Moreover, stress-elevated SNAI2 expression is mediated by FOXO3, which activatesSNAI2transcription by directly binding to its promoter. Herein, FOXO3 and SNAI2 form a coherent feed-forward regulatory loop to reinforce autophagy genes induction in response to energy stress. Strikingly, a dFoxO-Snail feed-forward circuit also regulates autophagy inDrosophila, suggesting this mechanism is evolutionarily conserved from fly to human.

摘要：Flag leaf angle impacts the photosynthetic capacity of densely grown plants and is thus an important agronomic breeding trait for crop architecture and yield. The hormone auxin plays a key role in regulating this trait, yet the underlying molecular and cellular mechanisms remain unclear. Here, we report that two rice (Oryza sativa) auxin response factors (ARFs), OsARF6 and OsARF17, which are highly expressed in lamina joint tissues, control flag leaf angle in response to auxin. Loss-of-function doubleosarf6 osarf17mutants displayed reduced secondary cell wall levels of lamina joint sclerenchymatous cells (Scs), resulting in an exaggerated flag leaf angle and decreased grain yield under dense planting conditions. Mechanical measurements indicated that the mutant lamina joint tissues were too weak to support the weight of the flag leaf blade, resembling the phenotype of the riceincreased leaf angle1(ila1) mutant. We demonstrate that OsARF6 and OsARF17 directly bind to theILA1promoter independently and synergistically to activate its expression. In addition, auxin-inducedILA1expression was dependent on OsARF6 and OsARF17. Collectively, our study reveals a mechanism that integrates auxin signaling with the secondary cell wall composition to determine flag leaf angle, providing breeding targets in rice, and potentially other cereals, for this key trait.

摘要：Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2responses. The introduction of themed8mutation in a constitutive oxidative stress genetic background (catalase-deficient,cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly,med8seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. Themed8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.

摘要：The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammation and host defense; however, the underlying molecular mechanism remains unclear. Here, we show that myocyte enhancer factor 2 C (MEF2C) is essential for regulating M1 macrophage polarization in response to infection and inflammation. Global gene expression analysis demonstrated that MEF2C deficiency in macrophages downregulated the expression of M1 phenotypic markers and upregulated the expression of M2 phenotypic markers. MEF2C significantly promoted the expression of interleukin-12 p35 subunit(Il12a)and interleukin-12 p40 subunit(Il12b). Myeloid-specificMef2c-knockout mice showed reduced IL-12 production and impaired Th1 responses, which led to susceptibility toListeria monocytogenesinfection and protected against DSS-induced IBD in vivo. Mechanistically, we showed that MEF2C directly activated the transcription ofIl12aandIl12b. These findings reveal a new function of MEF2C in macrophage polarization and Th1 responses and identify MEF2C as a potential target for therapeutic intervention in inflammatory and autoimmune diseases

摘要：Rationale:Peritoneal metastasis is one of the most common and life-threatening metastases in gastric cancer patients. The disseminated gastric cancer cells forming peritoneal metastasis exhibit a variety of characteristics that contrast with those of adjacent epithelial cell of gastric mucosa and even primary gastric cancer cells. We hypothesized that the gene expression profiles of peritoneal foci could reveal the identities of genes that might function as metastatic activator.Methods:In this study, we show, usingin vitro, in vivo, in silicoand gastric cancer tissues studies in humans and mice, that Homoebox A11 (HOXA11) potently promote peritoneal metastasis of gastric cancer cells.Results:Its mechanism of action involves alternation of cancer stemness and subsequently enhancement of the adhesion, migration and invasion and anti-apoptosis. This is achieved, mainly, through formation of a positive feedback loop between HOXA11 and Stat3, which is involved in the stimulation of Stat3 signaling pathway.Conclusions:These observations uncover a novel peritoneal metastatic activator and demonstrate the association between HOXA11, Stat3 and cancer stemness of gastric cancer cells, thereby revealing a previously undescribed mechanism of peritoneal metastasis.Keywords:BBI608; HOXA11; Stat3; gastric cancer; peritoneal metastasis.

摘要：The limited treatment options for the increasing occurrence of Lassahemorrhagic feverin West Africa poses an urgent need for the discovery and development of novel therapeutics. Dietary supplements, especially natural products that are edible and safe for human use, are a good source of drug discovery with potential for uncovering novel applications. In this study, we tested 40 natural products of dietary supplements and identifiedcapsaicin, a common dietary supplement abundant in chili peppers, as an inhibitor ofLassa virus(LASV) entry with EC50of 6.9–10.0μmol/L using an HIV based pseudovirus platform. Capsaicin inhibits the entry of five LASV strains but not against theOld World arenaviruslymphocytic choriomeningitis virus(LCMV), showing a preferential activity against LASV. Capsaicin inhibits LASV entry by blocking the pH dependent viral fusion through affecting the stablesignal peptide(SSP)-GP2 transmembrane (GP2TM) region of the LASV surfaceglycoprotein. Mutational study revealed the key residues Ala25, Val431, Phe434 and Val435 in SSP-GP2TMregion in capsaicin's antiviral effect. This study for the first time reveals a direct acting antiviral effect of capsaicin against the hemorrhagic fever causing LASV, providing detailed interaction hot spots in the unique SSP-GP2TMinterface of LASV glycoprotein that is crucial in fusion inhibition, and offering a new strategy in discovering and developing antivirals from natural products that are safe for human use.

摘要：Impressive clinical benefit is seen in clinic with PD‐1 inhibitors on portion of cancer patients. Yet, there remains an urgent need to develop effective synergizers to expand their clinical application. Tumor‐associated macrophage (TAM), a type of M2‐polarized macrophage, eliminates or suppresses T‐cell‐mediated anti‐tumor responses. Transforming TAMs into M1 macrophages is an attractive strategy of anti‐tumor therapy. Here, we conducted a high‐throughput screening and found that Carfilzomib potently drove M2 macrophages to express M1 cytokines, phagocytose tumor cells, and present antigens to T cells. Mechanistically, Carfilzomib elicited unfolded protein response (UPR), activated IRE1α to recruit TRAF2, and activated NF‐κB to transcribe genes encoding M1 markers in M2 macrophages.In vivo, Carfilzomib effectively rewired tumor microenvironment through reprogramming TAMs into M1‐like macrophages and shrank autochthonous lung cancers in transgenic mouse model. More importantly, Carfilzomib synergized with PD‐1 antibody to almost completely regress autochthonous lung cancers. Given the safety profiles of Carfilzomib in clinic, our work suggested a potentially immediate application of combinational treatment with Carfilzomib and PD‐1 inhibitors for patients with solid tumors.

摘要：Herein, we demonstrate that NFAT, a key regulator of the immune response, translocates from cytoplasm to nucleolus and interacts with NF45/NF90 complex to collaboratively promote rDNA transcription via triggering the directly binding of NF45/NF90 to the ARRE2-like sequences in rDNA promoter upon T-cell activationin vitro. The elevated pre-rRNA level of T cells is also observed in both mouse heart or skin transplantation models and in kidney transplanted patients. Importantly, T-cell activation can be significantly suppressed by inhibiting NF45/NF90-dependent rDNA transcription. Amazingly, CX5461, a rDNA transcription-specific inhibitor, outperformed FK506, the most commonly used immunosuppressant, both in terms of potency and off-target activity (i.e., toxicity), as demonstrated by a series of skin and heart allograft models. Collectively, this reveals NF45/NF90-mediated rDNA transcription as a novel signaling pathway essential for T-cell activation and as a new target for the development of safe and effective immunosuppressants.

摘要：The Notch signaling pathway controls cell growth, differentiation, and fate decisions, and its dysregulation has been linked to various human genetic disorders and cancers. To comprehensively understand the global organization of the Notch pathway and identify potential drug targets for Notch-related diseases, we established a protein interaction landscape for the human Notch pathway. By combining and analyzing genetic and phenotypic data with bioinformatics analysis, we greatly expanded this pathway and identified many key regulators, including low-density-lipoprotein-receptor-related protein 1 (LRP1). We demonstrated that LRP1 mediates the ubiquitination chain linkage switching of Delta ligands, which further affects ligand recycling, membrane localization, and stability. LRP1 inhibition led to Notch signaling inhibition and decreased tumorigenesis in leukemia models. Our study provides a glimpse into the Notch pathway interaction network and uncovers LRP1 as one critical regulator of the Notch pathway, as well as a possible therapeutic target for Notch-related cancers.