High-electrophilic (SiO)2Nb(OH)(=O) sites confined in silanol defects over Nb-Beta zeolite for efficient cyclic alkene epoxidation reactions.

Dealuminated Beta zeolite has a large amount of silanol defects on its interface, which provides an ideal place for embedding metal species and creating metal active sites in a confined microenvironment. The confined metal sites as well as their surroundings are closely related to the reactant activation and transient state achievement. Hence, unraveling the confined metal sites is of great significance for the catalytic reaction process. Herein, niobium species were incorporated into the silanol defects over dealuminated Beta zeolite with a facile dry impregnation method, co-grinding the niobium precursor with dealuminated Beta zeolite support. The successful incorporation of niobium into the silanol defects for 30Nb-Beta zeolite was verified by DRIFT, 1H MAS NMR, UV-Vis and UV-Raman characterizations. XAS characterization and DFT calculations further disclosed that the confined Nb species existed as (SiO)2Nb(OH)(=O), containing two Si-O-Nb bonds, one Nb=O bond as well as one Nb-OH bond. The synthesized 30Nb-Beta zeolite catalyst displayed a superior cyclohexene conversion of 51.1%, cyclohexene oxide selectivity of 83.1% as well as TOF value of 188.2 h-1 ascribed to the inherent electrophilicity of Nb(V) for confined (SiO)2Nb(OH)(=O) species as well as the low oxygen transfer energy barrier for NbV-OOH species. Furthermore, the prepared 30Nb-Beta zeolite can be effectively employed to other cyclic alkene epoxidation reactions.

Inhibition of CAF-1 histone chaperone complex triggers cytosolic DNA and dsRNA sensing pathways and induces intrinsic immunity of hepatocellular carcinoma.

BACKGROUND AND AIMS: Chromatin assembly factor 1 (CAF-1) is a replication-dependent epigenetic regulator that controls cell cycle progression and chromatin dynamics. In this study, we aim to investigate the immunomodulatory role and therapeutic potential of the CAF-1 complex in HCC. APPROACH AND RESULTS: CAF-1 complex knockout cell lines were established using the CRISPR/Cas9 system. The effects of CAF-1 in HCC were studied in HCC cell lines, nude mice, and immunocompetent mice. RNA-sequencing, ChIP-Seq, and assay for transposase accessible chromatin with high-throughput sequencing (ATAC-Seq) were used to explore the changes in the epigenome and transcriptome. CAF-1 complex was significantly upregulated in human and mouse HCCs and was associated with poor prognosis in patients with HCC. Knockout of CAF-1 remarkably suppressed HCC growth in both in vitro and in vivo models. Mechanistically, depletion of CAF-1 induced replicative stress and chromatin instability, which eventually led to cytoplasmic DNA leakage as micronuclei. Also, chromatin immunoprecipitation sequencing analyses revealed a massive H3.3 histone variant replacement upon CAF-1 knockout. Enrichment of euchromatic H3.3 increased chromatin accessibility and activated the expression of endogenous retrovirus elements, a phenomenon known as viral mimicry. However, cytosolic micronuclei and endogenous retroviruses are recognized as ectopic elements by the stimulator of interferon genes and dsRNA viral sensing pathways, respectively. As a result, the knockout of CAF-1 activated inflammatory response and antitumor immune surveillance and thereby significantly enhanced the anticancer effect of immune checkpoint inhibitors in HCC. CONCLUSIONS: Our findings suggest that CAF-1 is essential for HCC development; targeting CAF-1 may awaken the anticancer immune response and may work cooperatively with immune checkpoint inhibitor treatment in cancer therapy.

The Role of Gluten in Food Products and Dietary Restriction: Exploring the Potential for Restoring Immune Tolerance.

Wheat is extensively utilized in various processed foods due to unique proteins forming from the gluten network. The gluten network in food undergoes morphological and molecular structural changes during food processing, affecting the final quality and digestibility of the food. The present review introduces the formation of the gluten network and the role of gluten in the key steps of the production of several typical food products such as bread, pasta, and beer. Also, it summarizes the factors that affect the digestibility of gluten, considering that different processing conditions probably affect its structure and properties, contributing to an in-depth understanding of the digestion of gluten by the human body under various circumstances. Nevertheless, consumption of gluten protein may lead to the development of celiac disease (CD). The best way is theoretically proposed to prevent and treat CD by the inducement of oral tolerance, an immune non-response system formed by the interaction of oral food antigens with the intestinal immune system. This review proposes the restoration of oral tolerance in CD patients through adjunctive dietary therapy via gluten-encapsulated/modified dietary polyphenols. It will reduce the dietary restriction of gluten and help patients achieve a comprehensive dietary intake by better understanding the interactions between gluten and food-derived active products like polyphenols.

L-type calcium ion channel-mediated activation of autophagy in vascular smooth muscle cells via thonningianin A (TA) alleviates vascular calcification in type 2 diabetes mellitus.

Vascular calcification (VC) is associated with increased morbidity and mortality, especially among people with type 2 diabetes mellitus (T2DM). The pathogenesis of vascular calcification is incompletely understood, and until now, there have been no effective therapeutics for vascular calcification. The L-type calcium ion channel in the cell membrane is vital for Ca2+ influx. The effect of L-type calcium ion channels on autophagy remains to be elucidated. Here, the natural compound thonningianin A (TA) was found to ameliorate vascular calcification in T2DM via the activation of L-type calcium ion channels. The results showed that TA had a concentration-dependent ability to decrease the transcriptional and translational expression of the calcification-related proteins runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteopontin (OPN) (P < 0.01) via ATG7-dependent autophagy in ß-glycerophosphate (ß-GP)- and high glucose (HG)-stimulated primary mouse aortic smooth muscle cells (MASMCs) and alleviate aortic vascular calcification in VitD3-stimulated T2DM mice. However, nifedipine, an inhibitor of L-type calcium ion channels, reversed TA-induced autophagy and Ca2+ influx in MASMCs. Molecular docking analysis revealed that TA was located in the hydrophobic pocket of Cav1.2 α1C and was mainly composed of the residues Ile, Phe, Ala and Met, which confirmed the efficacy of TA in targeting the L-type calcium channel of Cav1.2 on the cell membrane. Moreover, in an in vivo model of vascular calcification in T2DM mice, nifedipine reversed the protective effects of TA on aortic calcification and the expression of the calcification-related proteins RUNX2, BMP2 and OPN (P < 0.01). Collectively, the present results reveal that the activation of cell membrane L-type calcium ion channels can induce autophagy and ameliorate vascular calcification in T2DM. Thonningianin A (TA) can target and act as a potent activator of L-type calcium ion channels. Thus, this research revealed a novel mechanism for autophagy induction via L-type calcium ion channels and provided a potential therapeutic for vascular calcification in T2DM.

Histone chaperone FACT complex coordinates with HIF to mediate an expeditious transcription program to adapt to poorly oxygenated cancers.

Cancer cells adapt to hypoxia through HIFs (hypoxia-inducible factors), which initiate the transcription of numerous genes for cancer cell survival in the hypoxia microenvironment. In this study, we find that the FACT (facilitates chromatin transcription) complex works cooperatively with HIFs to facilitate the expeditious expression of HIF targets for hypoxia adaptation. Knockout (KO) of the FACT complex abolishes HIF-mediated transcription by impeding transcription elongation in hypoxic cancer cells. Interestingly, the FACT complex is post-translationally regulated by PHD/VHL-mediated hydroxylation and proteasomal degradation, in similar fashion to HIF-1/2α. Metabolic tracing confirms that FACT KO suppresses glycolytic flux and impairs lactate extrusion, leading to intracellular acidification and apoptosis in cancer cells. Therapeutically, hepatic artery ligation and anti-angiogenic inhibitors adversely induce intratumoral hypoxia, while co-treatment with FACT inhibitor curaxin remarkably hinders the growth of hypoxic tumors. In summary, our findings suggest that the FACT complex is a critical component of hypoxia adaptation and a therapeutic target for hypoxic tumors.

IL-1ß in atherosclerotic vascular calcification: From bench to bedside.

Atherosclerotic vascular calcification contributes to increased risk of death in patients with cardiovascular diseases. Assessing the type and severity of inflammation is crucial in the treatment of numerous cardiovascular conditions. IL-1ß, a potent proinflammatory cytokine, plays diverse roles in the pathogenesis of atherosclerotic vascular calcification. Several large-scale, population cohort trials have shown that the incidence of cardiovascular events is clinically reduced by the administration of anti-IL-1ß therapy. Anti-IL-1ß therapy might reduce the incidence of cardiovascular events by affecting atherosclerotic vascular calcification, but the mechanism underlying this effect remains unclear. In this review, we summarize current knowledge on the role of IL-1ß in atherosclerotic vascular calcification, and describe the latest results reported in clinical trials evaluating anti-IL-1ß therapies for the treatment of cardiovascular diseases. This review will aid in improving current understanding of the pathophysiological roles of IL-1ß and mechanisms underlying its activity.

Bromodomain-containing protein BRPF1 is a therapeutic target for liver cancer.

Epigenetic deregulation plays an essential role in hepatocellular carcinoma (HCC) progression. Bromodomains are epigenetic "readers" of histone acetylation. Recently, bromodomain inhibitors have exhibited promising therapeutic potential for cancer treatment. Using transcriptome sequencing, we identified BRPF1 (bromodomain and PHD finger containing 1) as the most significantly upregulated gene among the 43 bromodomain-containing genes in human HCC. BRPF1 upregulation was significantly associated with poor patient survival. Gene ablation or pharmacological inactivation of BRPF1 significantly attenuated HCC cell growth in vitro and in vivo. BRPF1 was involved in cell cycle progression, senescence and cancer stemness. Transcriptome sequencing revealed that BRPF1 is a master regulator controlling the expression of multiple key oncogenes, including E2F2 and EZH2. We demonstrated that BRPF1 activated E2F2 and EZH2 expression by facilitating promoter H3K14 acetylation through MOZ/MORF complex. In conclusion, BRPF1 is frequently upregulated in human HCCs. Targeting BRPF1 may be an approach for HCC treatment.

Ammonium removal using a calcined natural zeolite modified with sodium nitrate.

Ammonium is one of the key factors responsible for the eutrophication of water bodies. The purpose of this study was to remove ammonium from water using a natural zeolite (NZ) modified with sodium nitrate (NaNO3) by impregnation and calcination. The ability of the NZ to remove ammonium from water was determined by single calcination; however, its efficiency was significantly enhanced by impregnation with a NaNO3 solution. Zeolite modified with 3.00 M NaNO3 and calcination at 673 K yielded the best ammonium removal efficiency, which was 39.88 % higher than the NZ alone. The zeolites that were regenerated over six times maintained a removal rate of 79.35-84.79 % by mixing 25.0 mg of the NZ into 50 mL of a 5.0 mg/L ammonium solution. The improved performance of the modified zeolite (qm, 16.96 mg/g) was mainly attributed to its relatively elevated mesopore volumes and higher ion-exchange capacity that results from nitrate decomposition, oxygen release, and sodium-ion exchange. The adsorption kinetics and isotherms are best described by the pseudo-first-order (PFO) and Freundlich model, respectively, and the process was endothermic. The effects of other factors, including coexisting ions, pH, and dosage, on ammonium adsorption were also determined.

Histone chaperone FACT complex mediates oxidative stress response to promote liver cancer progression.

OBJECTIVE: Facilitates Chromatin Transcription (FACT) complex is a histone chaperone participating in DNA repair-related and transcription-related chromatin dynamics. In this study, we investigated its oncogenic functions, underlying mechanisms and therapeutic implications in human hepatocellular carcinoma (HCC). DESIGN: We obtained HCC and its corresponding non-tumorous liver samples from 16 patients and identified FACT complex as the most upregulated histone chaperone by RNA-Seq. We further used CRISPR-based gene activation and knockout systems to demonstrate the functions of FACT complex in HCC growth and metastasis. Functional roles and mechanistic insights of FACT complex in oxidative stress response were investigated by ChIP assay, flow cytometry, gene expression assays and 4sU-DRB transcription elongation assay. Therapeutic effect of FACT complex inhibitor, Curaxin, was tested in both in vitro and in vivo models. RESULTS: We showed that FACT complex was remarkably upregulated in HCC and contributed to HCC progression. Importantly, we unprecedentedly revealed an indispensable role of FACT complex in NRF2-driven oxidative stress response. Oxidative stress prevented NRF2 and FACT complex from KEAP1-mediated protein ubiquitination and degradation. Stabilised NRF2 and FACT complex form a positive feedback loop; NRF2 transcriptionally activates the FACT complex, while FACT complex promotes the transcription elongation of NRF2 and its downstream antioxidant genes through facilitating rapid nucleosome disassembly for the passage of RNA polymerase. Therapeutically, Curaxin effectively suppressed HCC growth and sensitised HCC cell to sorafenib. CONCLUSION: In conclusion, our findings demonstrated that FACT complex is essential for the expeditious HCC oxidative stress response and is a potential therapeutic target for HCC treatment.

Genome-wide CRISPR/Cas9 library screening identified PHGDH as a critical driver for Sorafenib resistance in HCC.

Sorafenib is the standard treatment for advanced hepatocellular carcinoma (HCC). However, the development of drug resistance is common. By using genome-wide CRISPR/Cas9 library screening, we identify phosphoglycerate dehydrogenase (PHGDH), the first committed enzyme in the serine synthesis pathway (SSP), as a critical driver for Sorafenib resistance. Sorafenib treatment activates SSP by inducing PHGDH expression. With RNAi knockdown and CRISPR/Cas9 knockout models, we show that inactivation of PHGDH paralyzes the SSP and reduce the production of αKG, serine, and NADPH. Concomitantly, inactivation of PHGDH elevates ROS level and induces HCC apoptosis upon Sorafenib treatment. More strikingly, treatment of PHGDH inhibitor NCT-503 works synergistically with Sorafenib to abolish HCC growth in vivo. Similar findings are also obtained in other FDA-approved tyrosine kinase inhibitors (TKIs), including Regorafenib or Lenvatinib. In summary, our results demonstrate that targeting PHGDH is an effective approach to overcome TKI drug resistance in HCC.

RNA N6-methyladenosine methyltransferase-like 3 promotes liver cancer progression through YTHDF2-dependent posttranscriptional silencing of SOCS2.

Epigenetic alterations have contributed greatly to human carcinogenesis. Conventional epigenetic studies have predominantly focused on DNA methylation, histone modifications, and chromatin remodeling. Recently, diverse and reversible chemical modifications of RNAs have emerged as a new layer of epigenetic regulation. N6-methyladenosine (m6A) is the most abundant chemical modification of eukaryotic messenger RNA (mRNA) and is important for the regulation of mRNA stability, splicing, and translation. Using transcriptome sequencing, we discovered that methyltransferase-like 3 (METTL3), a major RNA N6-adenosine methyltransferase, was significantly up-regulated in human hepatocellular carcinoma (HCC) and multiple solid tumors. Clinically, overexpression of METTL3 is associated with poor prognosis of patients with HCC. Functionally, we proved that knockdown of METTL3 drastically reduced HCC cell proliferation, migration, and colony formation in vitro. Knockout of METTL3 remarkably suppressed HCC tumorigenicity and lung metastasis in vivo. On the other hand, using the CRISPR/dCas9-VP64 activation system, we demonstrated that overexpression of METTL3 significantly promoted HCC growth both in vitro and in vivo. Through transcriptome sequencing, m6A sequencing, and m6A methylated RNA immuno-precipitation quantitative reverse-transcription polymerase chain reaction, we identified suppressor of cytokine signaling 2 (SOCS2) as a target of METTL3-mediated m6A modification. Knockdown of METTL3 substantially abolished SOCS2 mRNA m6A modification and augmented SOCS2 mRNA expression. We also showed that m6A-mediated SOCS2 mRNA degradation relied on the m6A reader protein YTHDF2-dependent pathway. CONCLUSION: METTL3 is frequently up-regulated in human HCC and contributes to HCC progression. METTL3 represses SOCS2 expression in HCC through an m6A-YTHDF2-dependent mechanism. Our findings suggest an important mechanism of epigenetic alteration in liver carcinogenesis. (Hepatology 2018;67:2254-2270).

Diethylnitrosamine-induced expression of germline-specific genes and pluripotency factors, including vasa and oct4, in medaka somatic cells.

Various methods have been developed to reprogram mammalian somatic cells into pluripotent cells as well as to directly reprogram somatic cells into other cell lineages. We are interested in applying these methods to fish, and here, we examined whether mRNA expression of germline-specific genes (vasa, nanos2, -3) and pluripotency factors (oct4, sox2, c-myc, nanog) is inducible in somatic cells of Japanese medaka (Oryzias latipes). We found that the expression of vasa is induced in the gut and regenerating fin by exposure to a carcinogen, diethylnitrosamine (DEN). Induction of vasa in the gut started on the 5th day of treatment with >50 ppm DEN. In addition, nanos2, -3, oct4, sox2, klf4, c-myc, and nanog were also expressed simultaneously in some vasa-positive gut and regenerating fin samples. Vasa-positive cells were detected by immunohistochemistry (IHC) in the muscle surrounding the gut and in the wound epidermis, blastema, and fibroblast-like cells in regenerating fin. In vasa:GFP transgenic medaka, green fluorescent protein (GFP) fluorescence appeared in the wound epidermis and fibroblast-like cells in the regenerating fin following DEN exposure, in agreement with the IHC data. Our data show that mRNA expression of genes relevant to germ cell specification and pluripotency can be induced in fish somatic cells by exposure to DEN, suggesting the possibility of efficient and rapid cell reprogramming of fish somatic cells.