Myricetin induces M2 macrophage polarization to alleviate renal tubulointerstitial fibrosis in diabetic nephropathy via PI3K/Akt pathway.

BACKGROUND: Development of end-stage renal disease is predominantly attributed to diabetic nephropathy (DN). Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue. Nevertheless, the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain. AIM: To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism. METHODS: Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk. Subsequently, blood and urine indexes were assessed, along with examination of renal tissue pathology. Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin, periodic acid-Schiff, Masson's trichrome, and Sirius-red. Additionally, high-glucose culturing was conducted on the RAW 264.7 cell line, treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h. In both in vivo and in vitro settings, quantification of inflammation factor levels was conducted using western blotting, real-time qPCR and ELISA. RESULTS: In db/db mice, administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis. Notably, we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin, along with a decrease in expressions of inflammatory cytokine-related factors. Furthermore, myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha, interleukin-6, and interluekin-1ß induced by high glucose in RAW 264.7 cells. Additionally, myricetin modulated the M1-type polarization of the RAW 264.7 cells. Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin. The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002. CONCLUSION: This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

Fructose sweetens the adipocyte-T cell alliance against tumors.

Dietary fructose is implicated in tumorigenesis, but whether dietary fructose regulates antitumor immunity remains elusive. In this issue of Cell Metabolism, Zhang et al. show that dietary fructose promotes adipocyte-derived leptin production, which attenuates terminal exhaustion programming and boosts the effector function of CD8+ T cells for improved tumor control.

Single-cell CRISPR screens in vivo map T cell fate regulomes in cancer.

CD8+ cytotoxic T cells (CTLs) orchestrate antitumour immunity and exhibit inherent heterogeneity1,2, with precursor exhausted T (Tpex) cells but not terminally exhausted T (Tex) cells capable of responding to existing immunotherapies3-7. The gene regulatory network that underlies CTL differentiation and whether Tex cell responses can be functionally reinvigorated are incompletely understood. Here we systematically mapped causal gene regulatory networks using single-cell CRISPR screens in vivo and discovered checkpoints for CTL differentiation. First, the exit from quiescence of Tpex cells initiated successive differentiation into intermediate Tex cells. This process is differentially regulated by IKAROS and ETS1, the deficiencies of which dampened and increased mTORC1-associated metabolic activities, respectively. IKAROS-deficient cells accumulated as a metabolically quiescent Tpex cell population with limited differentiation potential following immune checkpoint blockade (ICB). Conversely, targeting ETS1 improved antitumour immunity and ICB efficacy by boosting differentiation of Tpex to intermediate Tex cells and metabolic rewiring. Mechanistically, TCF-1 and BATF are the targets for IKAROS and ETS1, respectively. Second, the RBPJ-IRF1 axis promoted differentiation of intermediate Tex to terminal Tex cells. Accordingly, targeting RBPJ enhanced functional and epigenetic reprogramming of Tex cells towards the proliferative state and improved therapeutic effects and ICB efficacy. Collectively, our study reveals that promoting the exit from quiescence of Tpex cells and enriching the proliferative Tex cell state act as key modalities for antitumour effects and provides a systemic framework to integrate cell fate regulomes and reprogrammable functional determinants for cancer immunity.

No evident causal association between Helicobacter pylori infection and colorectal cancer: a bidirectional mendelian randomization study.

Observational studies have reported a correlation between Helicobacter pylori infection and colorectal cancer (CRC); however, the underlying cause has remained unclear. This research was aimed at determining whether there is a correlation between H. pylori infection and CRC by measuring the prevalence of H. pylori CagA antibodies and VacA antibodies. Using data from many genome-wide association studies (GWAS), we conducted a Mendelian randomization (MR) study with two sample GWAS. Then, we used bidirectional MR to evaluate the association between H. pylori infection and CRC for identifying causation. The most common method of analysis was the inverse variance-weighted technique. In addition, we performed supplementary analyses using the weighted median technique and MR-Egger regression. Horizontal pleiotropic outliers were identified and corrected using the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) method. Genetically predicted anti-H. pylori IgG seropositivity was not causally associated with CRC [odds ratio (OR): 1.12; 95% confidence interval (CI): 0.98-1.27, P = 0.08] and neither were H. pylori VacA antibody levels (OR = 0.96, 95% CI: 0.90-1.02, P = 0.25) or H. pylori CagA antibody levels (OR = 1.00, 95% CI: 0.93-1.07, P = 0.92). Furthermore, reverse MR analysis did not reveal evidence for a causal effect of CRC on H. pylori infection. The weighted median, the MR-Egger method, and MR-PRESSO yielded identical results. Using genetic data, MR analysis showed there was no evidence for a causal association between seroprevalence of H. pylori infection and CRC. The relationship between H. pylori infection and CRC requires further research.

Effects of SGLT2 inhibitors on hepatic fibrosis and steatosis: A systematic review and meta-analysis.

Objective: Clinical trials have shown that sodium-glucose cotransporter 2 inhibitors (SGLT2i) are closely associated with hepatic fibrosis and steatosis by FibroScan. This paper aimed at evaluating the effects of SGLT2i on hepatic fibrosis and steatosis, which are presented as liver stiffness measurement (LSM) and controlled attenuation parameter (CAP). Methods: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, China Science and Technology Journal Database, and Wanfang Database were searched for randomized clinical trials from database establishment to 30 November 2022 with no language restrictions. The risk of bias was evaluated by Collaboration Handbook. Software Stata 17 and Review Manager (version 5.3) were used for meta-analysis. Results: A total of eight articles including 686 patients were included. Compared with the control group, our results showed that SGLT2i could lower levels of LSM [MD = -0.82, 95%CI (-1.38, -0.25), p = 0.005] and CAP [MD = -12.80, 95%CI (-20.57, -5.03), p = 0.001]. Further subgroup analyses indicated that SGLT2i presented more advantages on longer treatment duration and more serious steatosis in decreasing LSM. For CAP, SGLT2i exhibited a clear advantage in subgroup analyses of longer treatment duration, younger people, dapagliflozin, worse fibrosis, and steatosis. Conclusion: SGLT2i could reduce LSM and CAP in contrast to other antihyperglycemic drugs. However, the included studies are not definitive, and well-designed, more multi-centered, blinded randomized clinical trials are warranted to definitively establish reliable evidence.

Two Stable Sodalite-Cage-Based MOFs for Highly Gas Selective Capture and Conversion in Cycloaddition Reaction.

Stable metal-organic frameworks, containing periodically arranged nanosized cages or pores and active Lewis acid-base sites, are considered ideal candidates for efficient heterogeneous catalysis. Herein, based on the light of reticular chemistry design principles, the ingenious assembly of two pyridine N-rich multifunctional triangular linkers, H3TBA [3,5-di (1h-tetrazol-5-yl) benzoic acid] and H2TZI [5-(1H-tetrazol-5-yl)isophthalic acid], with MnII formed PCP-33(Mn) and PCP-34(Mn), respectively. PCP-33(Mn) and PCP-34(Mn) are typical sod topology zeolitic metal-organic frameworks (ZMOFs) with hierarchical tetragonal micropores and metal organic polyhedral sodalite-like cages. The inner walls of these cages are modified by open metal sites MnII and Lewis acid-base sites of halide ions and N pyridine atoms. The characteristics of the cages' structures make two MOFs exhibit high surface area and a small window, which promote their outstanding gas capture ability (C2H2, 131.8 cm3 g-1; CO2, 77.9 cm3 g-1 at 273 K) and selective separation performance (C2H2/CH4, 226.2, CO2/CH4, 50.3 at 298 K), and are also suitable as catalytic reactors for metal/solvent-free chemical fixation of CO2 with epoxides to achieve high-efficiency CO2 conversion. Furthermore, they are greatly recyclable for several cycles while retaining their structural rigidity and catalytic activity.

Triphenylbenzene functionalized polyhedral oligomeric silsesquioxane fluorescence sensor for the selective analysis of trace nitrofurazone in aquatic product and cosmetics.

Nitrofurazone (NFZ) is carcinogenic and mutagenic to human in long-term ingestion, and it is prohibited to be added in food. In this work, a novel triphenylbenzene (TPB) functionalized fluorescent hybrid porous polymers (POSS@TPB) was constructed by using polyhedral oligomeric silsesquioxane (POSS) as the rigid group and TPB as the core unit of high fluorescence. The morphology and physicochemical properties of POSS@TPB were characterized in detail. Moreover, the synergistic effect of inner filter effect and photoinduced electron transfer is verified by experimental and simulation results. After condition optimization, a NFZ analysis method based on POSS@TPB probe was established with a linear range of 0.4-16.5 mg/L and a detection limit of 0.13 mg/L. In addition, the fluorescent probe has good stability, anti-interference and considerable reusability. At the same time, the selective analysis of trace NFZ in aquatic product and cosmetics was carried out with satisfied recoveries of 87%-110.6% and relative standard deviation less than 4.1%. And the results were verified by high-performance liquid chromatography method. Overall, this fluorescence sensor has excellent performance in NFZ analysis, which provides a broad application prospect for the repeatable and selective residue NFZ analysis in aquatic product and cosmetics.

Development and comparison of three 89Zr-labeled anti-CLDN18.2 antibodies to noninvasively evaluate CLDN18.2 expression in gastric cancer: a preclinical study.

BACKGROUND: Isoform 2 of claudin 18 (CLDN18.2) is overexpressed in gastric cancer and may be a promising imaging target. In this study, we constructed three anti-CLDN18.2 antibodies and compared them in preclinical experiments. METHODS: Screening from anti-CLDN18.2 nanobody library, we constructed three antibodies, anti-CLDN18.2 VHH (recombinant single-chain antibody fused with poly-histidine-tag), anti-CLDN18.2 VHH-ABD (recombinant single-chain antibody fused fused with albumin binding domain), and anti-CLDN18.2 VHH-Fc (recombinant single-chain antibody fused with IgG1-Fc) and radiolabeled with 89Zr. Affinity assay, in vitro stability, immunoactivity, blood pharmacokinetics, in vivo and ex vivo biodistribution study, specificity study, and immunohistochemical analysis were performed to assess these radiotracers. RESULTS: The EC50 were 12.21 nM, 2.48 nM, and 0.14 nM for anti-CLDN18.2 VHH, anti-CLDN18.2 VHH-ABD, and anti-CLDN18.2 VHH-Fc, respectively. 89Zr-anti-CLDN18.2 VHH demonstrated the lowest tumor uptake in PET imaging. Both 89Zr-anti-CLDN18.2 VHH-ABD and 89Zr-anti-CLDN18.2 VHH-Fc demonstrated high tumor accumulation, with highest ID%/g of 25.78 ± 5.60 at 24 h post-injection with 89Zr-anti-CLDN18.2 VHH-ABD and 49.43 ± 9.86 at 72 h post-injection with 89Zr-anti-CLDN18.2 VHH-Fc. The specificity of 89Zr-anti-CLDN18.2 VHH-Fc targeting CLDN18.2 was further confirmed by blocking study. The ex vivo biodistribution results were consistent with in vivo biodistribution data. For 89Zr-anti-CLDN18.2 VHH-ABD, tumor uptake was 21.46 ± 1.78 ID%/g at 12 h and 13.73 ± 2.22 ID%/g at 108 h. For 89Zr-anti-CLDN18.2 VHH-Fc, the tumor accumulation was 25.28 ± 3.83 ID%/g at 12 h and 40.13 ± 9.50 ID%/g at 108 h. Immunohistochemistry of the xenograft tissue revealed high and homogenous CLDN18.2 expression in CO-SNU620 tumor. CONCLUSION: Both anti-CLDN18.2 VHH-ABD and anti-CLDN18.2 VHH-Fc can be efficiently and stably radiolabeled with 89Zr for noninvasive imaging and quantification of CLDN18.2 expression in gastric cancer, of which 89Zr-anti-CLDN18.2 VHH-ABD seems to be the optimal choice balancing tumor uptake and liver background. They can provide essential information to select patients who are likely to benefit from CLDN18.2-targeted treatment.

A novel raiometric fluorescence probe based on silicon quantum dots and copper nanoclusters for visual assay of l-cysteine in milks.

l-cysteine (l-Cys) plays an important role in many physiological processes. The previously reported methodologies for l-Cys detection have many drawbacks, and thus the development of specific/sensitive approaches is crucial for its direct/quick assay in food matrices. Herein, silicon quantum dots (SiQDs) and glutathione-stabilized copper nanoclusters (CuNCs) were successfully synthesized and integrated as a ratiometric fluorescent probe for assay l-Cys assay in milks. The fluorescence of SiQDs was quenched by CuNCs through fluorescence resonance energy-transfer process. Upon addition of l-Cys, the 440-nm fluorescence of SiQDs changed insignificantly, while the 650-nm fluorescence of CuNCs decreased significantly. Ratiometric fluorescence signal was linear in the l-Cys concentration range of 0.25 µM to 2.5 mM with a detection limit of 75 nM and visual color changes from red to blue. The probe can realize rapid and portable detection without the participation of intermediate ions, and has good selectivity and accuracy for l-cysteine in milk samples.

[Culture and application of thymic organoids: a review].

The thymus is a pivotal immune organ of the human body, and it is the place where T cells differentiate and mature. The damage of thymus would easily induce autoimmune diseases and even malignant tumors. For years, researchers have been exploring the process of T cell development and revealing the mechanism of thymic injury and regeneration generally through the monolayer culture system of T cells in vitro. However, the classic monolayer culture system could neither reproduce the unique three-dimensional epithelial reticular structure of the thymus, nor provide the cytokines and growth factors required for the directed differentiation of hematopoietic stem cells into T cells. Thymic organoid technology utilizes cells with stem cell potential to simulate the anatomical structure of the thymus and the signaling pathway mediated by thymic epithelial cells in vitro through three-dimensional culture, which is particularly close to the microenvironment of the thymus in vivo. Thymic organoids show great potential in the study of T cell differentiation and development, thymus-related diseases, reconstruction of immune function, and cell therapy. This paper summarizes the methods for culturing thymic organoids, followed by comparing the advantages and disadvantages of the scaffolds used for culturing. The applications of thymic organoids in the disease model, tumor-targeting therapy, regenerative medicine, and organ transplantation were also discussed, with possible future research directions prospected.

CRISPR screens unveil signal hubs for nutrient licensing of T cell immunity.

Nutrients are emerging regulators of adaptive immunity1. Selective nutrients interplay with immunological signals to activate mechanistic target of rapamycin complex 1 (mTORC1), a key driver of cell metabolism2-4, but how these environmental signals are integrated for immune regulation remains unclear. Here we use genome-wide CRISPR screening combined with protein-protein interaction networks to identify regulatory modules that mediate immune receptor- and nutrient-dependent signalling to mTORC1 in mouse regulatory T (Treg) cells. SEC31A is identified to promote mTORC1 activation by interacting with the GATOR2 component SEC13 to protect it from SKP1-dependent proteasomal degradation. Accordingly, loss of SEC31A impairs T cell priming and Treg suppressive function in mice. In addition, the SWI/SNF complex restricts expression of the amino acid sensor CASTOR1, thereby enhancing mTORC1 activation. Moreover, we reveal that the CCDC101-associated SAGA complex is a potent inhibitor of mTORC1, which limits the expression of glucose and amino acid transporters and maintains T cell quiescence in vivo. Specific deletion of Ccdc101 in mouse Treg cells results in uncontrolled inflammation but improved antitumour immunity. Collectively, our results establish epigenetic and post-translational mechanisms that underpin how nutrient transporters, sensors and transducers interplay with immune signals for three-tiered regulation of mTORC1 activity and identify their pivotal roles in licensing T cell immunity and immune tolerance.

Anticoagulation may contribute to antimicrobial treatment of Lemierre syndrome: a case report.

BACKGROUND: Lemierre syndrome (LS) is characterized by multisystemic infection beginning in the oropharynx, local thrombophlebitis (typically, of the internal jugular vein) and peripheral embolism. No evidence-based guidelines exist for the management of this disease, and the use of anticoagulation therapy remains particularly controversial. CASE PRESENTATION: A 61-year-old man presenting with left neck swelling, odynophagia, and dyspnea underwent emergency surgery and received intravenous antibiotics. The primary infection was controlled on hospital day 5, but on day 6 sudden leukocytosis and hypoxemia were observed. CT angiography revealed an intraluminal filling defect in the pulmonary artery on day 8. LS was diagnosed and anticoagulation therapy was initiated. The WBC count, which had maintained its peak values in the previous 2 days, decreased instantly after initiation, and follow-up controls showed thrombus resolution. CONCLUSIONS: Our case supports the notion that anticoagulation therapy may be a valid supplement to antimicrobial therapy in LS, especially in the presence of a possibly young thrombus as suggested by clinical worsening.

Metabolic control of TFH cells and humoral immunity by phosphatidylethanolamine.

T follicular helper (TFH) cells are crucial for B cell-mediated humoral immunity1. Although transcription factors such as BCL6 drive the differentiation of TFH cells2,3, it is unclear whether and how post-transcriptional and metabolic programs enforce TFH cell programming. Here we show that the cytidine diphosphate (CDP)-ethanolamine pathway co-ordinates the expression and localization of CXCR5 with the responses of TFH cells and humoral immunity. Using in vivo CRISPR-Cas9 screening and functional validation in mice, we identify ETNK1, PCYT2, and SELENOI-enzymes in the CDP-ethanolamine pathway for de novo synthesis of phosphatidylethanolamine (PE)-as selective post-transcriptional regulators of TFH cell differentiation that act by promoting the surface expression and functional effects of CXCR5. TFH cells exhibit unique lipid metabolic programs and PE is distributed to the outer layer of the plasma membrane, where it colocalizes with CXCR5. De novo synthesis of PE through the CDP-ethanolamine pathway co-ordinates these events to prevent the internalization and degradation of CXCR5. Genetic deletion of Pcyt2, but not of Pcyt1a (which mediates the CDP-choline pathway), in activated T cells impairs the differentiation of TFH cells, and this is associated with reduced humoral immune responses. Surface levels of PE and CXCR5 expression on B cells also depend on Pcyt2. Our results reveal that phospholipid metabolism orchestrates post-transcriptional mechanisms for TFH cell differentiation and humoral immunity, highlighting the metabolic control of context-dependent immune signalling and effector programs.

In vivo therapeutic effects of affinity-improved-TCR engineered T-cells on HBV-related hepatocellular carcinoma.

BACKGROUND: In patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), virus-specific cytotoxic T lymphocytes (CTLs) fail to eliminate HCC cells expressing HBV antigens. As the expression of viral antigen in HBV-associated HCC may decrease to allow tumor to escape immune attacks, we hypothesized that an HBV surface antigen (HBsAg)-specific affinity-improved-T-cell receptor (TCR) will enable T cells to target HCC more effectively than corresponding wild-type-TCR. We also postulated that TCR promiscuity can be exploited to efficiently capture HBV variants that can hinder CTL-based therapeutics. METHODS: We applied flexi-panning to isolate affinity-improved TCRs binding to a variant antigen, the human leukocyte antigen (HLA)-A*02:01-restricted nonapeptide HBs371-379-ILSPFLPLL, from libraries constructed with a TCR cloned using the decapeptide HBs370-379-SIVSPFIPLL. The potency and safety of the affinity-improved-TCR engineered T-cells (Ai-TCR-T) were verified with potentially cross-reactive human and HBV-variant peptides, tumor and normal cells, and xenograft mouse models. RESULTS: Ai-TCR-T cells retained cognate HBV antigen specificity and recognized a wide range of HBV genotypic variants with improved sensitivity and cytotoxicity. Cell infusions produced complete elimination of HCC without recurrence in the xenograft mouse models. Elevated accumulation of CD8+ Ai-TCR-T cells in tumors correlated with tumor shrinkage. CONCLUSION: The in vitro and in vivo studies demonstrated that HBsAg-specific Ai-TCR-T cells had safety profiles similar to those of their wild-type counterparts and significantly enhanced potency. This study presents an approach to develop new therapeutic strategies for HBV-related HCC.

AGK Unleashes CD8+ T Cell Glycolysis to Combat Tumor Growth.

Elevated glycolytic metabolism is essential for CD8+ T cell antitumor function, but cell-intrinsic factors modulating this process remain elusive. In this issue, Hu et al. (2019) show that the lipid kinase acylglycerol kinase (AGK) promotes the glycolytic and functional fitness of CD8+ T cells by inactivating PTEN and boosting mTOR activity, thereby promoting antitumor activity.

The nuclear receptor corepressor NCoR1 regulates hematopoiesis and leukemogenesis in vivo.

Enhanced understanding of normal and malignant hematopoiesis pathways should facilitate the development of effective clinical treatment strategies for hematopoietic malignancies. Nuclear receptor corepressor 1 (NCoR1) has been implicated in transcriptional repression and embryonic organ development, but its role in hematopoiesis is yet to be fully elucidated. Here, we showed that hematopoietic-specific loss of NCoR1 leads to expansion of the hematopoietic stem cell (HSC) pool due to aberrant cell cycle entry of long-term HSCs under steady-state conditions. Moreover, NCoR1-deficient HSCs exhibited normal self-renewal capacity but severely impaired lymphoid-differentiation potential in competitive hematopoietic-reconstitution assays. Transcriptome analysis further revealed that several hematopoiesis-associated genes are regulated by NCoR1. In addition, NCoR1 deficiency in hematopoietic cells delayed the course of leukemia and promoted leukemia cell differentiation in an MLL-AF9-induced mouse model. NCoR1 and its partner, histone deacetylase 3, can modulate histone acetylation and gene transcription through binding the promoter regions of myeloid-differentiation genes. Our collective results support the critical involvement of NCoR1 in normal and malignant hematopoiesis in vivo.

Tetramethylpyrazine­2'O­sodium ferulate provides neuroprotection against neuroinflammation and brain injury in MCAO/R rats by suppressing TLR-4/NF-κB signaling pathway.

BACKGROUND: Neuroinflammation following cerebral ischemia is a serious risk factor in stroke patients. The purpose of this study was to investigate the neuroprotective effects of tetramethylpyrazine­2'O­sodium ferulate (TSF), a structurally modified compound from tetramethylpyrazine and ferulate, on cerebral ischemic injury and the underlying mechanisms. METHODS: Focal transient cerebral ischemia was induced in rat for 2 h by middle cerebral artery occlusion (MCAO) and the protective effect of TSF was studied using different doses of the drug (10.8, 18, 30 mg/kg, intravenously); Ozagrel (18 mg/kg) was used as the positive control. The drugs were given immediately after MCAO and the efficacy and mechanisms were evaluated at 72 h of reperfusion. The level of pro-inflammatory cytokines such as TNF-α, IL-1ß and anti-inflammatory molecules such as IL-10 was measured; other factors such as neurological deficit, brain water content and infarct size and the level of MCP-1, ICAM-1, iNOS, CD11b, TLR-4/NF-κBp65 were also measured. RESULTS: TSF at the doses of 18, 30 mg/kg significantly improved neurological deficit, reduced brain water content and infarct size, accompanied by a decrease in the concentration of TNF-α, IL-1ß, MCP-1, ICAM-1, iNOS and an increase in the concentration of IL-10. The amount of CD11b and ICAM-1 was found largely decreased and the expression of TLR-4 and the nuclear NF-κBp65 was weakened in TSF-treatment group. CONCLUSIONS: Our study suggests that TSF possesses a neuroprotective effect against ischemic stroke which might be mediated through suppression of the inflammatory pathways in the brain following ischemic stroke.

Oncolytic effect of wild-type Newcastle disease virus isolates in cancer cell lines in vitro and in vivo on xenograft model.

Oncolyic virotherapy is one of the modern experimental techniques to treat human cancers. Here we studied the antitumor activity of wild-type Newcastle disease virus (NDV) isolates from Russian migratory birds. We showed that NDV could selectively kill malignant cells without affecting healthy cells. We evaluated the oncolytic effect of 44 NDV isolates in 4 histogenetically different human cell lines (HCT116, HeLa, A549, MCF7). The safety of the isolates was also tested in normal peripheral blood mononuclear (PBMC) cells. The viability of tumor cell lines after incubation with NDV isolates was evaluated by MTT. All cell lines, except for normal PBMC primary cells, had different degrees of susceptibility to NDV infection. Seven NDV strains had the highest oncolytic activity, and some NDV strains demonstrated oncolytic selectivity for different cell lines. In vivo, we described the intratumoral activity of NDV/Altai/pigeon/770/2011 against subcutaneous non-small cell lung carcinoma using xenograft SCID mice model. All animals were responsive to therapy. Histology confirmed therapy-induced destructive changes and growing necrotic bulk density in tumor tissue. Our findings indicate that wild-type NDV strains selectively kill tumor cells with no effect on healthy PBMC cells, and intratumoral virotherapy with NDV suppresses the subcutaneous tumor growth in SCID mice.

MLL5 suppresses antiviral innate immune response by facilitating STUB1-mediated RIG-I degradation.

Trithorax group protein MLL5 is an important epigenetic modifier that controls cell cycle progression, chromatin architecture maintenance, and hematopoiesis. However, whether MLL5 has a role in innate antiviral immunity is largely unknown. Here we show that MLL5 suppresses the RIG-I-mediated anti-viral immune response. Mll5-deficient mice infected with vesicular stomatitis virus show enhanced anti-viral innate immunity, reduced morbidity, and viral load. Mechanistically, a fraction of MLL5 located in the cytoplasm interacts with both RIG-I and its E3 ubiquitin ligase STUB1, which promotes K48-linked polyubiquitination and proteasomal degradation of RIG-I. MLL5 deficiency attenuates the RIG-I and STUB1 association, reducing K48-linked polyubiquitination and accumulation of RIG-I protein in cells. Upon virus infection, nuclear MLL5 protein translocates from the nucleus to the cytoplasm inducing STUB1-mediated degradation of RIG-I. Our study uncovers a previously unrecognized role for MLL5 in antiviral innate immune responses and suggests a new target for controlling viral infection.

The chromatin remodeling subunit Baf200 promotes normal hematopoiesis and inhibits leukemogenesis.

BACKGROUND: Adenosine triphosphate (ATP)-dependent chromatin remodeling SWI/SNF-like BAF and PBAF complexes have been implicated in the regulation of stem cell function and cancers. Several subunits of BAF or PBAF, including BRG1, BAF53a, BAF45a, BAF180, and BAF250a, are known to be involved in hematopoiesis. Baf200, a subunit of PBAF complex, plays a pivotal role in heart morphogenesis and coronary artery angiogenesis. However, little is known on the importance of Baf200 in normal and malignant hematopoiesis. METHODS: Utilizing Tie2-Cre-, Vav-iCre-, and Mx1-Cre-mediated Baf200 gene deletion combined with fetal liver/bone marrow transplantation, we investigated the function of Baf200 in fetal and adult hematopoiesis. In addition, a mouse model of MLL-AF9-driven leukemogenesis was used to study the role of Baf200 in malignant hematopoiesis. We also explored the potential mechanism by using RNA-seq, RT-qPCR, cell cycle, and apoptosis assays. RESULTS: Tie2-Cre-mediated loss of Baf200 causes perinatal death due to defective erythropoiesis and impaired hematopoietic stem cell expansion in the fetal liver. Vav-iCre-mediated loss of Baf200 causes only mild anemia and enhanced extramedullary hematopoiesis. Fetal liver hematopoietic stem cells from Tie2-Cre + , Baf200 f/f or Vav-iCre + , Baf200 f/f embryos and bone marrow hematopoietic stem cells from Vav-iCre + , Baf200 f/f mice exhibited impaired long-term reconstitution potential in vivo. A cell-autonomous requirement of Baf200 for hematopoietic stem cell function was confirmed utilizing the interferon-inducible Mx1-Cre mouse strain. Transcriptomes analysis revealed that expression of several erythropoiesis- and hematopoiesis-associated genes were regulated by Baf200. In addition, loss of Baf200 in a mouse model of MLL-AF9-driven leukemogenesis accelerates the tumor burden and shortens the host survival. CONCLUSION: Our current studies uncover critical roles of Baf200 in both normal and malignant hematopoiesis and provide a potential therapeutic target for suppressing the progression of leukemia without interfering with normal hematopoiesis.