摘要：As the second most common malignant bone tumor in children and adolescents, Ewing sarcoma is initiated and exacerbated by a chimeric oncoprotein, most commonly, EWS-FLI1. In this study, we apply epigenomic analysis to characterize the transcription dysregulation in this cancer, focusing on the investigation of super-enhancer and its associated transcriptional regulatory mechanisms. We demonstrate that super-enhancer-associated transcripts are significantly enriched in EWS-FLI1 target genes, contribute to the aberrant transcriptional network of the disease, and mediate the exceptional sensitivity of Ewing sarcoma to transcriptional inhibition. Through integrative analysis, we identify MEIS1 as a super-enhancer-driven oncogene, which co-operates with EWS-FLI1 in transcriptional regulation, and plays a key pro-survival role in Ewing sarcoma. Moreover, APCDD1, another super-enhancer-associated gene, acting as a downstream target of both MEIS1 and EWS-FLI1, is also characterized as a novel tumor-promoting factor in this malignancy. These data delineate super-enhancer-mediated transcriptional deregulation in Ewing sarcoma, and uncover numerous candidate oncogenes which can be exploited for further understanding of the molecular pathogenesis for this disease.

摘要：Rationale:Endothelial dysfunction results in sustained and chronic vascular inflammation, which is central to atherosclerotic diseases. However, transcriptional regulation of vascular endothelial inflammation has not been well clarified.Objective:This study aims to explore Foxp (forkhead box P) transcription factor 1 in regulation of endothelial homeostasis, atherogenesis, and its mechanisms.Methods and Results:To assess the importance of Foxp1 in atherosclerosis, Foxp1 expression was analyzed in human coronary artery and mouse artery, and we observed significant downregulation of Foxp1 in atherosclerotic and atherosusceptible endothelium. Endothelial-specific Foxp1 knockout mice (Foxp1ECKO) were bred ontoApoeKOmice to generate endothelial Foxp1-deletion hyperlipidemic modelFoxp1ECKO;ApoeKO, which displayed significant increases in atherosclerotic lesion formation in aortas and aortic roots with enhanced monocyte adhesion, migration, and infiltration into the vascular wall and formation of inflammatory lipid-laden macrophages. In contrast, endothelial-specific Foxp1 overexpression miceFoxp1ECTg;ApoeKOexhibited reduced atherosclerotic lesion formation with less monocyte infiltration. Foxp1 was further identified as a gatekeeper of vessel inflammation by direct regulation of endothelial inflammasome components, including Nlrp3 (NLR [nucleotide-binding and leucine-rich repeat immune receptors] family pyrin domain containing 3), caspase-1, and IL (interleukin)-1β. Moreover, endothelial Foxp1 was found to be regulated by Klf2 (Kruppel-like factor 2). Oscillatory shear stress downregulated Foxp1 expression via repressing Klf2 expression in endothelium, and, therefore, promoted endothelial inflammasome activation, leading to atherosclerotic lesion formation. Simvastatin upregulated the reduced expression of Klf2 and Foxp1 in atherosusceptible vascular endothelium and alleviated vascular inflammation contributing to its inhibitory effect in atherosclerosis.Conclusions:These data are the first in vivo experimental validation of an atheroprotective role of endothelial Klf2 and Foxp1, which reveals a Klf2-Foxp1 transcriptional network in endothelial cells as a novel regulator of endothelial inflammasome activation for atherogenesis, therefore, provides opportunities for therapeutic intervention of atherosclerotic diseases and uncovers a novel atheroprotective mechanism for simvastatin.

摘要：Background and aims:Bone is the second most frequent site of metastasis for HCC, which leads to an extremely poor prognosis. HCC bone metastasis is typically osteolytic, involving the activation of osteoclasts. Long noncoding RNA H19 plays an important role in the pathogenesis of human cancers. Nonetheless, the mechanism underlying the participation of H19 in HCC bone metastasis remains unclear.Approach and results:The current study established a mouse HCC bone metastasis model by using serial intracardiac injection and cell isolation to obtain cells with distinct bone metastasis ability. H19 was highly expressed in these cells and in clinical HCC bone metastasis specimens. Both osteoclastogenesis in vitro and HCC bone metastasis in vivo were promoted by H19 overexpression, whereas these processes were suppressed by H19 knockdown. H19 overexpression attenuated p38 phosphorylation and further down-regulated the expression of osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor. However, up-regulated OPG expression as well as suppressed osteoclastogenesis caused by H19 knockdown were recovered by p38 interference, indicating that p38 mitogen-activated protein kinase (MAPK)-OPG contributed to H19-promoted HCC bone metastasis. Furthermore, we demonstrated that H19 inhibited the expression of OPG by binding with protein phosphatase 1 catalytic subunit alpha (PPP1CA), which dephosphorylates p38. SB-203580-mediated inactivation of p38MAPK reversed the down-regulation of HCC bone metastasis caused by H19 knockdown in vivo. Additionally, H19 enhanced cell migration and invasion by up-regulating zinc finger E-box binding homeobox 1 through the sequestration of microRNA (miR) 200b-3p.Conclusions:H19 plays a critical role in HCC bone metastasis by reducing OPG expression, which is mediated by the PPP1CA-induced inactivation of the p38MAPK pathway; and H19 also functions as a sponge for miR-200b-3p.

摘要：Metabolic homeostasis of amino acids is essential for human health. Here, we aimed to investigate a potential role for the clock component reverse erythroblastosis virus α (Rev-erbα) in circadian regulation of amino acid metabolism. RNA-seq withRev-erbα-/-mice showed expression changes in genes involved in amino acid metabolism, particularly, the urea cycle and methionine metabolism. Rev-erbα ablation increased hepatic mRNA, protein, and enzymatic activity of betaine homocysteine methyltransferase (Bhmt), cystathionine β-synthase (Cbs), and cystathionine γ-lyase (Cth) and decreased the levels of plasma and liver homocysteine in mice. Cell-based assays confirmed negative regulation of these three genes by Rev-erbα. Combined luciferase reporter, mobility-shift, and chromatin immunoprecipitation assays identified Rev-erbα as a transcriptional repressor ofBhmt,Cbs, andCth. Rev-erbα ablation or antagonism alleviated chemical-induced hyperhomocysteinemia in mice. This was accompanied by elevated expressions of Bhmt, Cbs, and Cth. Moreover, Rev-erbα ablation or antagonism promoted urea production and ammonia clearance. Of urea cycle–related genes, arginase 1 (Arg1), ornithine transcarbamylase (Otc), and carbamoyl-phosphate synthase 1 (Cps1) expressions were up-regulated inRev-erbα-/-mice. Negative regulation of these urea cycle genes by Rev-erbα was validated using cell-based experiments. Mechanistic studies revealed that Rev-erbα inhibited CCAAT-enhancer-binding protein α transactivation to repress the transcription ofArg1,Cps1, andOtc.Conclusion:Rev-erbα antagonism alleviates hyperhomocysteinemia and promotes ammonia clearance. Targeting Rev-erbα represents an approach for the management of homocysteine- and ammonia-related diseases.

摘要：PGAM5 is a mitochondrial serine/threoninephosphatasethat regulates multiple metabolic pathways and contributes to tumorigenesis in a poorly understood manner. We show here that PGAM5 inhibition attenuates lipid metabolism and colorectal tumorigenesis in mice. PGAM5-mediateddephosphorylationof malic enzyme 1 (ME1) at S336 allows increased ACAT1-mediated K337acetylation, leading to ME1dimerizationand activation, both of which are reversed by NEK1 kinase-mediated S336 phosphorylation.SIRT6deacetylase antagonizes ACAT1 function in a manner that involves mutually exclusive ME1 S336 phosphorylation and K337 acetylation. ME1 also promotesnicotinamide adenine dinucleotide phosphate(NADPH) production,lipogenesis, and colorectal cancers in which ME1 transcripts are upregulated and ME1 protein is hypophosphorylated at S336 and hyperacetylated at K337. PGAM5 and ME1 upregulation occur via directtranscriptional activationmediated by β-catenin/TCF1. Thus, the balance between PGAM5-mediated dephosphorylation of ME1 S336 and ACAT1-mediated acetylation of K337 strongly influences NADPH generation, lipid metabolism, and the susceptibility to colorectal tumorigenesis.

摘要：Triple-negative breast cancer (TNBC) is the most challenging subtype of breast cancer. Various endeavor has been made to explore the molecular biology basis of TNBC. Herein, we reported a novel function of factor Kinectin 1 (KTN1) as a carcinogenic promoter in TNBC. KTN1 expression in TNBC was increased compared with adjacent tissues or luminal or Her2 subtypes of breast cancer, and TNBC patients with high KTN1 expression have poor prognosis. In functional studies, knockdown of KTN1 inhibited the proliferation and invasiveness of TNBC both in vitro and in vivo, while overexpression of KTN1 promoted cancer cell proliferation and invasiveness. RNA-seq analysis revealed that the interaction of cytokine-cytokine receptor, particularly CXCL8 gene, was upregulated by KTN1, which was supported by the further experiments. CXCL8 depletion inhibited the tumorigenesis and progression of TNBC. Additionally, rescue experiments validated that KTN1-mediated cell growth acceleration in TNBC was dependent on CXCL8 both in vitro and in vivo. Furthermore, it was found that KTN1 enhanced the phosphorylation of NF-κB/p65 protein at Ser536 site, and specifically bound to NF-κB/p65 protein in the nucleus and cytoplasm of cells. Moreover, the transcription of CXCL8 gene was directly upregulated by the complex of KTN1 and NF-κB/p65 protein. Taken together, our results elucidated a novel mechanism of KTN1 gene in TNBC tumorigenesis and progression. KTN1 may be a potential molecular target for the development of TNBC treatment.

摘要：New variants of SARS-CoV-2 have been emerging since the initial outbreak in 2019;1 one of the latest ones was identified in Southern California in October 2020 and was subsequently detected in 26 other states in the United States as well as other countries as of January 2021. This strain, derived from coronavirus D614G mutation, is characterized by three genetic variations leading to three novel amino acid substitutions (S13I, W152C, and L452R) in the spike (S) protein (Supplementary Fig. S1). The S13I and W152C are in the N-terminal domain, and more importantly, the L452R is located in the receptor-binding domain (RBD) (Supplementary Fig. S3).

摘要：Background:Acute ischemic stroke (AIS) is a leading cause of disability and mortality worldwide. Prediction of penumbra existence after AIS is crucial for making decision on reperfusion therapy. Yet a fast, inexpensive, simple, and noninvasive predictive biomarker for the poststroke penumbra with clinical translational potential is still lacking. We aim to investigate whether the CircOGDH (circular RNA derived from oxoglutarate dehydrogenase) is a potential biomarker for penumbra in patients with AIS and its role in ischemic neuronal damage.Methods:CircOGDH was screened from penumbra of middle cerebral artery occlusion mice and was assessed in plasma of patients with AIS by quantitative polymerase chain reaction. Magnetic resonance imaging was used to examine the penumbra volumes. CircOGDH interacted with miR-5112 (microRNA-5112) in primary cortical neurons was detected by fluorescence in situ hybridization, RNA immunoprecipitation, and luciferase reporter assay. Adenovirus-mediated CircOGDH knockdown ameliorated neuronal apoptosis induced byCOL4A4(Gallus collagen, type IV, alpha IV) overexpression. Transmission electron microscope, nanoparticle tracking analysis, and Western blot were performed to confirm exosomes.Results:CircOGDH expression was dramatically and selectively upregulated in the penumbra tissue of middle cerebral artery occlusion mice and in the plasma of 45 patients with AIS showing a 54-fold enhancement versus noncerebrovascular disease controls. Partial regression analysis revealed that CircOGDH expression was positively correlated with the size of penumbra in patients with AIS. Sequestering of miR-5112 by CircOGDH enhancedCOL4A4expression to elevate neuron damage. Additionally, knockdown of CircOGDH significantly enhanced neuronal cell viability under ischemic conditions. Furthermore, the expression of CircOGDH in brain tissue was closely related to that in the serum of middle cerebral artery occlusion mice. Finally, we found that CircOGDH was highly expressed in plasma exosomes of patients with AIS compared with those in noncerebrovascular disease individuals.Conclusions:These results demonstrate that CircOGDH is a potential therapeutic target for regulating ischemic neuronal viability, and is enriched in neuron-derived exosomes in the peripheral blood, serving as a predictive biomarker of penumbra in patients with AIS.

摘要：Background and AimsNASH is associated with high levels of cholesterol and triglyceride (TG) in the liver; however, there is still no approved pharmacological therapy. Synthesis of cholesterol and TG is controlled by sterol regulatory element-binding protein (SREBP), which is found to be abnormally activated in NASH patients. We aim to discover small molecules for treating NASH by inhibiting the SREBP pathway.Approach and ResultsHere, we identify a potent SREBP inhibitor, 25-hydroxylanosterol (25-HL). 25-HL binds to insulin-induced gene (INSIG) proteins, stimulates the interaction between INSIG and SCAP, and retains them in the endoplasmic reticulum, thereby suppressing SREBP activation and inhibiting lipogenesis. In NASH mouse models, 25-HL lowers levels of cholesterol and TG in serum and the liver, enhances energy expenditure to prevent obesity, and improves insulin sensitivity. 25-HL dramatically ameliorates hepatic steatosis, inflammation, ballooning, and fibrosis through down-regulating the expression of lipogenic genes. Furthermore, 25-HL exhibits both prophylactic and therapeutic efficacies of alleviating NASH and atherosclerosis in amylin liver NASH model diet-treatedLdlr?/?mice, and reduces the formation of cholesterol crystals and associated crown-like structures of Kupffer cells. Notably, 25-HL lowers lipid contents in serum and the liver to a greater extent than lovastatin or obeticholic acid. 25-HL shows a good safety and pharmacokinetics profile.ConclusionsThis study provides the proof of concept that inhibiting SREBP activation by targeting INSIG to lower lipids could be a promising strategy for treating NASH. It suggests the translational potential of 25-HL in human NASH and demonstrates the critical role of SREBP-controlled lipogenesis in the progression of NASH by pharmacological inhibition.

摘要：In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.