Isoliquiritigenin limits inflammasome activation of macrophage via docking into Syk to alleviate murine non-alcoholic fatty liver disease.

Isoliquiritigenin (ISL) is a chalcone-type flavonoid derived from the root of licorice with antioxidant, anti-inflammatory, anti-tumour and neuroprotective properties. ISL has been proven to downregulate the productions of IL-1ß, TNF-α and IL-6 by macrophages. However, detailed molecular mechanisms of this modulation remain elusive. Here, ISL suppressed Syk phosphorylation and CD80, CD86, IL-1ß, TNF-α and IL-6 expressions in lipopolysaccharide-stimulated macrophages ex vivo. ApoC3-transgenic (ApoC3TG) mice had more activated macrophages. ISL was also able to downregulate the inflammatory activities of macrophages from ApoC3TG mice. Administration of ISL inhibited Syk activation and inflammatory activities of macrophages in ApoC3TG mice in vivo. The treatment of ISL further alleviated MCD-induced non-alcoholic fatty liver disease (NAFLD) in wild-type and ApoC3TG mice, accompanied by less recruitment and activation of liver macrophages. Due to the inhibition of Syk phosphorylation, ISL-treated macrophages displayed less production of cytoplasmic ROS, NLRP3, cleaved-GSDMD and cleaved-IL-1ß, suggesting less inflammasome activation. Finally, the molecular docking study demonstrated that ISL bound to Syk directly with the Kd of 1.273 × 10-8 M. When the Syk expression was knocked down by its shRNA, the inhibitory effects of ISL on activated macrophages disappeared, indicating that Syk was at least one of key docking-molecules of ISL. Collectively, ISL could alleviate MCD-induced NAFLD in mice involved with the inhibition of macrophage inflammatory activity by the blockade of Syk-induced inflammasome activation.

Low-dose adropin stimulates inflammasome activation of macrophage via mitochondrial ROS involved in colorectal cancer progression.

Adropin is encoded by the energy homeostasis-associated (ENHO) gene and widely present in liver, pancreas, heart, kidney, brain, and vascular tissues. Abnormal adropin is associated with metabolic, inflammatory, immune, and central nervous disorders. Whether adropin is involved in the development of colorectal cancer (CRC) is still unclear. Here, decreased adropin expression of tumor-nest cells in advanced-stage CRC was demonstrated. Adropin expressed by carcinoma cells was negatively correlated with macrophage infiltration in the matrix of CRC tissues. However, tumor macrophages enhanced adropin expression and were positively correlated with tumor invasion and metastasis. ENHO gene transfection into colon cancer (MC38) cells inhibited tumor growth in vivo, accompanying the increase of M1 macrophages. Treatment with low-dose adropin (< 100 ng/mL) on macrophages ex vivo directly increased mitochondrial reactive oxygen species for inflammasome activation. Furthermore, ENHO-/- mice had less M1 macrophages in vivo, and ENHO-/- macrophages were inert to be induced into the M1 subset ex vivo. Finally, low-dose adropin promoted glucose utilization, and high-dose adropin enhanced the expression of CPT1α in macrophages. Therefore, variations of adropin level in carcinoma cells or macrophages in tumor tissues are differently involved in CRC progression. Low-dose adropin stimulates the antitumor activity of macrophages, but high-dose adropin facilitates the pro-tumor activity of macrophages. Increasing or decreasing the adropin level can inhibit tumor progression at different CRC stages.

Apolipoprotein C-III itself stimulates the Syk/cPLA2-induced inflammasome activation of macrophage to boost anti-tumor activity of CD8+ T cell.

Increased prevalence of cancer in obese individuals is involved with dyslipidemia- induced chronic inflammation and immune suppression. Although apolipoprotein C-III (ApoC3)-transgenic mice (ApoC3TG mice) or poloxamer 407 (P407)-treated mice had hyperlipidemia, CD8+ T cells with upregulated antitumor activities were observed in ApoC3TG mice, and decreased CD8+ T cell activities were observed in P407-treated mice. Increased ApoC3 expression in hepatocellular carcinoma was associated with increased infiltration of CD8+ T cells and predicted survival. Recombinant ApoC3 had no direct effects on CD8+ T cells. The upregulation of CD8+ T cells in ApoC3TG mice was due to cross-talk with context cells, as indicated by metabolic changes and RNA sequencing results. In contrast to dendritic cells, the macrophages of ApoC3TG mice (macrophagesTG) displayed an activated phenotype and increased IL-1ß, TNF-α, and IL-6 production. Coculture with macrophagesTG increased CD8+ T cell function, and the adoptive transfer of macrophagesTG suppressed tumor progression in vivo. Furthermore, spleen tyrosine kinase (Syk) activation induced by TLR2/TLR4 cross-linking after ApoC3 ligation promoted cellular phospholipase A2 (cPLA2) activation, which in turn activated NADPH oxidase 2 (NOX2) to promote an alternative mode of inflammasome activation. Meanwhile, mitochondrial ROS produced by increased oxidative phosphorylation of free fatty acids facilitated the classical inflammasome activation, which exerted an auxiliary effect on inflammasome activation of macrophagesTG. Collectively, the increased antitumor activity of CD8+ T cells was mediated by the ApoC3-stimulated inflammasome activation of macrophages, and the mimetic ApoC3 peptides that can bind TLR2/4 could be a future strategy to target liver cancer.

B-N/B-O Contained Heterocycles as Fusion Locker in Multi-Resonance Frameworks towards Highly-efficient and Stable Ultra-Narrowband Emission.

Fusing condensed aromatics into multi-resonance (MR) frameworks has been an exquisite strategy to modulate the optoelectronic properties, which, however, always sacrifices the small full width at half maxima (FWHM). Herein, we strategically embed B-N/B-O contained heterocycles as fusion locker into classical MR prototypes, which could enlarge the π-extension and alleviate the steric repulsion for an enhanced planar skeleton to suppress the high-frequency stretching/ scissoring vibrations for ultra-narrowband emissions. Sky-blue emitters with extremely small FWHMs of 17-18 nm are thereafter obtained for the targeted emitters, decreased by (1.4-1.9)-fold compared with the prototypes. Benefiting from their high photoluminescence quantum yields of >90 % and fast radiative decay rates of >108  s-1 , one of those emitters shows a high maximum external quantum efficiency of 31.9 % in sensitized devices, which remains 25.8 % at a practical luminance of 1,000 cd m-2 with a small FWHM of merely 19 nm. Notably a long operation half-lifetime of 1,278 h is also recorded for the same device, representing one of the longest lifetimes among sky-blue devices based on MR emitters.

High-Efficiency Narrowband Multi-Resonance Emitter Fusing Indolocarbazole Donors for BT. 2020 Red Electroluminescence and Ultralong Operation Lifetime.

Polycyclic heteroaromatics with multi-resonance (MR) characteristics are attractive materials for narrowband emitters in wide-color-gamut organic light-emitting diodes. However, MR emitters with pure-red colors are still rare and usually exhibit problematic spectral broadening when redshifting emission. Here, a narrowband pure-red MR emitter is reported by fusing indolocarbazole segments into a boron/oxygen-embedded skeleton, realizing BT.2020 red electroluminescence for the first time together with a high efficiency and an ultralong lifetime. The rigid indolocarbazole segment possesses a strong electron-donating ability due to its para-positioned nitrogen-π-nitrogen backbone and also enlarges the π-extension of the MR skeleton to suppress structural displacement during radiation, achieving concurrently redshifted and narrowed emission spectrum. An emission maximum at 637 nm with a full width at half-maxima of merely 32 nm (0.097 eV) is recorded in toluene. The corresponding device simultaneously exhibits CIE coordinates of (0.708, 0.292) precisely matching the BT.2020 red point, a high external quantum efficiency of 34.4% with low roll-off and an ultralong LT95 (time to 95% of the initial luminance) of >10 000 h at 1000 cd m-2 . These performance characteristics are superior even to those of state-of-the-art perovskite and quantum-dot-based devices for this specific color, paving the way toward practical applications.

One-Shot Synthesis of B/N-Doped Calix[4]arene Exhibiting Narrowband Multiple Resonance Fluorescence.

A novel macrocycle of B/N-doped calix[4]arene (C-BN) was synthesized by a one-shot double boronation. Owing to the structural tension and electron-donating properties of the nitrogen atoms in the macrocycle, reaction selectively proceeds between the adjacent benzene rings outside the macrocycle. C-BN shows a highly centrosymmetric structure with two multiple resonance (MR) fragments bridged by tertiary amine groups at the 1,3 positions of the benzene ring. Benefiting from the large intermolecular distance (>4.6 Å) between adjacent MR-emitting cores, C-BN also exhibits excellent narrowband emitting features against aggregation-induced quenching and spectrum broadening. Optimized organic light-emitting diode devices based on C-BN exhibit high maximum external quantum efficiencies of 24.7-26.6 % and small full width at half maximums of 25-28 nm over a wide doping range of 1-12 wt %.

microRNA-144/451 decreases dendritic cell bioactivity via targeting interferon-regulatory factor 5 to limit DSS-induced colitis.

The microRNAs miR-144/451 are highly conserved miRNA that is strongly induced during erythropoiesis. Despite the biological functions of miR-144/451 have been extensively studied in erythropoiesis and tumorigenesis, few studies have been conducted in immune responses. In this study, we showed that miR-144/451-/- DCs exhibit increased activation. Mechanistically, the miR-144 directly targets the 3`-UTR of IRF5 and represses the expression of IRF5 in DCs. Ectopic expression of miR-144/451 by lentiviruses downregulates the levels of IRF5 and suppresses DCs function. In addition, knockdown of IRF5 by shRNA significantly inhibits activities of the miR-144/451-/- DCs. Expression of miR144/451 was decreased in DCs from both patients with IBD and mice with DSS-colitis compared with controls. Human PBMC derived DCs were downregulated expression of miR144/451 after LPS stimulation. In the DSS-induced colitis mice model, we showed that ablation of the miR-144/451 gene causes severe colitis, and their DCs from both periphery and MLN expressed higher co-stimulatory molecules and pro-inflammatory cytokines than wild-type mice. In addition, DCs isolated from miR-144/451-/- mice transfusion exacerbates mice colitis. In the bone marrow transplanted chimeric mice model, we show that miR-144/451-/- bone marrow transplantation deteriorated DSS-induced colitis. At last, we treat the mice with miR-144/451 delivered by chitosan nanoparticles revealing protective effects in DSS-induced colitis mice. Thus, our results reveal a novel miR144/451-IRF5 pathway in DCs that protects experimental colitis. The manipulation of miR-144/451 expression and DCs activation in IBD patients may be a novel therapeutic approach for the treatment of inflammatory diseases.

Nitrogen-Embedded Multi-Resonance Heteroaromatics with Prolonged Homogeneous Hexatomic Rings.

Nitrogen-containing polycyclic heteroaromatics have exhibited fascinating multi-resonance (MR) characteristics for efficient narrowband emission, but strategies to bathochromic shift their emissions while maintaining the narrow bandwidths remain exclusive. Here, homogeneous hexatomic rings are introduced into nitrogen-embedded MR skeletons to prolong the π-conjugation length for low-energy electronic transitions while retaining the non-bonding character of the remaining parts. The proof-of-the-concept emitters exhibit near unity photoluminescence quantum yields with peaks at 598 nm and 620 nm and small full-width-at-half-maximums of 28 nm and 31 nm, respectively. Optimal organic light-emitting diodes exhibit a high external quantum efficiency of 18.2 %, negligible efficiency roll-off, and ultra-long lifetime with negligible degradation at an initial luminance of 10 000 cd m-2 after 94 hours.

Insufficiency of FZR1 disturbs HSC quiescence by inhibiting ubiquitin-dependent degradation of RUNX1 in aplastic anemia.

FZR1 has been implicated as a master regulator of the cell cycle and quiescence, but its roles and molecular mechanisms in the pathogenesis of severe aplastic anemia (SAA) are unclear. Here, we report that FZR1 is downregulated in SAA HSCs compared with healthy control and is associated with decreased quiescence of HSC. Haploinsufficiency of Fzr1 shows impaired quiescence and self-renewal ability of HSC in two Fzr1 heterozygous knockout mouse models. Mechanistically, FZR1 insufficiency inhibits the ubiquitination of RUNX1 protein at lysine 125, leading to the accumulation of RUNX1 protein, which disturbs the quiescence of HSCs in SAA patients. Moreover, downregulation of Runx1 reversed the loss of quiescence and impaired long-term self-renew ability in Fzr1+/- HSCs in vivo and impaired repopulation capacity in BM from SAA patients in vitro. Our findings, therefore, raise the possibility of a decisive role of the FZR1-RUNX1 pathway in the pathogenesis of SAA via deregulation of HSC quiescence.

Sterically Wrapped Multiple Resonance Fluorophors for Suppression of Concentration Quenching and Spectrum Broadening.

Multiple resonance (MR) emitters are promising for highly efficient organic light-emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with concentration-caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo-luminance quantum yields of ≥90 % and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1-20 wt %) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3-37.2 %, identical small FWHMs of 24 nm, and alleviated efficiency roll-offs in OLEDs.

Low miR-16 expression induces regulatory CD4+NKG2D+ T cells involved in colorectal cancer progression.

MiR-15a/16 is a member of the miRNA cluster that exhibits tumor suppression and immune modulation via targeting multiple genes. Decreased miR-15a/16 expression is involved in many cancer cells. Here, miR-16 had decreased expression in NK1.1-CD4+NKG2D+ T cells and bound with the 3'-UTR of NKG2D gene. MiR-15a/16-deficient mice had many CD4+NKG2D+ T cells, which produced TGF-ß1 and IL-10 and inhibited the IFN-γ production of CD8+ T cells. Adoptive transfer of NK1.1-CD4+NKG2D+ T cells from miR-15a/16-deficient mice promoted tumor growth in vivo. However, no changes for NK1.1-CD4+NKG2D+ T cells were found in the miR-15a/16-transgenic mice. Although the miR-15a/16 transgenic mice transplanted with B16BL6 or MC38 cells exhibited rapid growth, these tumor-bearing mice did not show changes in NK1.1-CD4+NKG2D+ T cell distributions in either spleens or tumors. When NK1.1-CD4+ T cells were stimulated by α-CD3/sRAE-1 ex vivo, the NKG2D expression was difficult to induce in the T cells of miR-15a/16-transgenic mice. Finally, increased frequencies of regulatory CD4+NKG2D+ T cells with low miR-16 levels were observed in patients with late-stage colorectal cancer (Duke's C, D). Thus, miR-16 modulates NK1.1-CD4+NKG2D+ T cell functions via targeting NKG2D. Low miR-16 expression in CD4+ T cells induces the regulatory CD4+NKG2D+ T subpopulation, which promotes tumor evasion via the secretion of immune-suppressive molecules.

Downregulation of NK cell activities in Apolipoprotein C-III-induced hyperlipidemia resulting from lipid-induced metabolic reprogramming and crosstalk with lipid-laden dendritic cells.

OBJECTIVE: Apolipoprotein C-III (Apoc3) is a key component of triglyceride-rich lipoproteins (TRL). The Apoc3-transgenic mice are characterized by high levels of plasma triglyceride and free fatty acids (FFAs). Apoc3 stimulates human monocytes via activation of the NLRP3 inflammasome. Considering the NK cell downregulation in obese individuals and the possible stimulatory-effects of macrophages, variations of NK cell functions and underlying mechanisms were investigated in mice with Apoc3-induced hyperlipidemia. METHODS: Variations of activities and glycolipid metabolism in NK cells of the Apoc3-transgenic mice with hyperlipidemia were detected. Molecular mechanisms of lipid-induced metabolic-reprogramming in NK cells were analyzed based on the transcriptome sequencing. Finally, effects of DCs in mice with hyperlipidemia on NK cell functions were determined. RESULTS: Impaired number and function of NK cells in Apoc3TG mice was involved with the increased fatty acid oxidation and decreased glycolysis. Increased uptake of FFAs in Apoc3TG-NK cells contributed to the peroxisome proliferator-activated receptor (PPAR) activation and the downstream PTEN-AKT-mTOR/FOXO1 signaling pathway. Inhibition of PPAR or CPT1α only partly reversed the IFN-γ production of Apoc3TG-NK cells, but completely restored IFN-γ secretion by palmitic acid-treated NK cells ex vivo, indicating that other factors contributed to the Apoc3TG-NK cell downregulation. Meanwhile, Apoc3TG-DCs, which contained more lipids in the cytoplasm, depended on reactive oxygen species (ROS) to increase the expressions PD-L1, TGF-ß1, and NKG2D ligands and suppress NK cell activities. DCs of the Apoc3TG-CD36-/+ hybrid mice with less intracellular lipids and ROS production could not inhibit NK cells, indicating that intracellular FFAs promoted the immune-modulatory function of DCs. CONCLUSIONS: The downregulation of NK cell activities in individuals with Apoc3-induced hyperlipidemia was due to the increased fatty acid oxidation in NK cells and the bystander suppression caused by lipid-laden DCs. The dual recovery function of NK cells and DCs would improve the prognosis of patients with metabolic syndrome.

Deficiency of miR-15a/16 upregulates NKG2D in CD8+ T cells to exacerbate dextran sulfate sodium-induced colitis.

The miR-15a/16 gene cluster is located in human chromosome 13 (13q14.3) and mouse chromosome 14 (14qC3). These genes are involved in cancer development and immune regulation. Our group has previously verified the binding of the 3'-untranslated region of NKG2D gene by miR-16 through dual-luciferase reporter assay. Herein, we found that miR-16 overexpression inhibited the NKG2D expression of CD8+ T cells, and that CD8+ NKG2D+ T cell frequency increased in miR-15/16-/- mice. CD8+ NKG2D+ T cells derived of miR-15/16-/- mice displayed activatory phenotype with enhanced IFN-γ production and cytotoxicity. The transfection of lentivirus containing antago-miR-16 sequences enhanced the NKG2D expression level of CD8+ T cells. However, no significant differences in CD8+ NKG2D+ T cell frequencies existed between wild-type and miR-15/16-transgenic mice because NKG2D was not expressed on the rest CD8+ T cells. When CD8+ T cells of miR-15/16-transgenic mice were treated with IL-2 in vitro, the magnitude of NKG2D expression and activation of CD8+ T cells was lower than that of wild-type mice. miR-15/16-/- mice showed that the exacerbation of colitis induced by dextran sulfate sodium (DSS) with more CD8+ T cells accumulated in inflamed colons, whereas miR-15/16-transgenic mice ameliorated DSS-induced colitis with less infiltration of CD8+ T cells. When NKG2D+ cells were depleted with NKG2D antibody in miR-15/16-/- mice, the aggravated colitis disappeared. All these results demonstrated that NKG2D could be upregulated by decreased miR-16 in CD8+ T cells to mediate inflammation. Thus, gene therapy based on the overexpression of miR-16 in CD8+ T cells can be used for patients with inflammatory diseases.

Early growth response genes 2 and 3 induced by AP-1 and NF-κB modulate TGF-ß1 transcription in NK1.1- CD4+ NKG2D+ T cells.

NK1.1- CD4+ NKG2D+ T cells are a subpopulation of regulatory T cells that downregulate the functions of CD4+ T, CD8+ T, natural killer (NK) cells, and macrophages through TGF-ß1 production. Early growth response genes 2 (Egr2) and 3 (Egr3) maintain immune homeostasis by modulating T lymphocyte development, inhibiting effector T cell function, and promoting the induction of regulatory T cells. Whether Egr2 and Egr3 directly regulate TGF-ß1 transcription in NK1.1- CD4+ NKG2D+ T cells remains elusive. The expression levels of Egr2 and Egr3 were higher in NK1.1- CD4+ NKG2D+ T cells than in NK1.1- CD4+ NKG2D- T cells. Egr2 and Egr3 expression were remarkably increased after stimulating NK1.1- CD4+ NKG2D+ T cells with sRAE or α-CD3/sRAE. The ectopic expression of Egr2 or Egr3 resulted in the enhancement of TGF-ß1 expression, while knockdown of Egr2 or Egr3 led to the decreased expression of TGF-ß1 in NK1.1- CD4+ NKG2D+ T cells. Egr2 and Egr3 directly bound with the TGF-ß1 promoter as demonstrated by the electrophoretic mobility shift assay and dual-luciferase gene reporter assay. Furthermore, the Egr2 and Egr3 expression of NK1.1- CD4+ NKG2D+ T cells could be induced by the AP-1 and NF-κB transcriptional factors, but had no involvement with the activation of NF-AT and STAT3. In conclusion, Egr2 and Egr3 induced by AP-1 and NF-κB directly initiate TGF-ß1 transcription in NK1.1- CD4+ NKG2D+ T cells. This study indicates that manipulating Egr2 and Egr3 expression would potentiate or alleviate the regulatory function of NK1.1- CD4+ NKG2D+ T cells and this strategy could be used in the therapy for patients with autoimmune diseases or tumor.

Erratum: Angiopoietin-like 4 deficiency upregulates macrophage function through the dysregulation of cell-intrinsic fatty acid metabolism.

[This corrects the article on p. 595 in vol. 10, PMID: 32195030.].

Angiopoietin-like 4 deficiency upregulates macrophage function through the dysregulation of cell-intrinsic fatty acid metabolism.

Angiopoietin-like 4 (ANGPLT4) regulates lipid metabolism by inhibiting lipoprotein lipase. Abnormal ANGTPL4 levels are associated with metabolic syndrome, atherosclerosis, inflammation, and cancer. We show here that ANGPTL4-deficient mice have abnormally large numbers of macrophages in the spleen, and that these macrophages produce large amounts of TNF-α, CD86, and inducible nitric oxide synthase. However, recombinant ANGPTL4 protein did not inhibit macrophage function ex vivo. Glycolysis and fatty-acid synthesis were upregulated in ANGPTL4-/- macrophages, whereas fatty-acid oxidation was decreased. Elevated levels of free fatty acids in the cytoplasm of ANGPTL4-/- macrophages were confirmed. ANGPTL4-/- macrophages also displayed endoplasmic reticulum (ER) stress after stimulation with LPS. Protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling was activated, but no major change in liver kinase B1 (LKB1)/adenosine 5'-monophosphate (AMP)- activated protein kinase (AMPK) phosphorylation was observed in ANGPTL4-/- macrophages. The modulation of fatty-acid metabolism prevented ER stress and the expression of inflammatory molecules, but the activation of ANGPTL4-/- macrophages was not restored by the inhibition of glycolysis. Thus, ANGPTL4 deficiency in macrophages results in ER stress due to the cell-intrinsic reprogramming of fatty-acid metabolism. Intracellular ANGPLT4 expression could thus be manipulated to modulate macrophage function.

Astilbin promotes the induction of regulatory NK1.1- CD4+ NKG2D+ T cells through the PI3K, STAT3, and MAPK signaling pathways.

Astilbin is a potential agent for autoimmune and inflammatory diseases and has a protective effect in mice with DSS-induced colitis. NK1.1- CD4+ NKG2D+ T cells are a subpopulation of regulatory T cells that produce TGF-ß1 and IL-10. Whether astilbin directly promotes the induction of NK1.1- CD4+ NKG2D+ T cells and whether these astilbin-stimulated T cells exert an immune-regulatory role remain unclear. Here, we show that astilbin efficiently induces the production of NK1.1- CD4+ NKG2D+ T cells with high expressions of TGF-ß1, IL-10, CCR6, and CCR9 in a dose-dependent manner ex vivo. These regulatory T cells also substantially inhibit the activities of CD8+ T cells and macrophages. Intraperitoneal injection of astilbin ameliorates the severity of colitis with an increase in the frequency of NK1.1- CD4+ NKG2D+ T cells in the colon tissue of DSS-treated mice. Moreover, adoptive transfer of NK1.1- CD4+ NKG2D+ T cells induced by astilbin remarkably protects against the onset of DSS-induced colitis. Finally, the PI3K, STAT3, and MAPK signaling pathways are involved in the induction of NK1.1- CD4+ NKG2D+ T cells by astilbin. Taken together, our study elucidates a new immune-regulatory mechanism of astilbin by inducing the regulatory NK1.1- CD4+ NKG2D+ T cells and indicates a potential clinical use of astilbin for patients with inflammatory bowel diseases.

Anti-tumor Effect of Ginkgo biloba Exocarp Extracts on B16 Melanoma Bearing Mice Involving P I3K/Akt/HIF-1α/VEGF Signaling Pathways.

The objective of this study is to investigate the anti-tumor effect of Ginkgo biloba exocarp extracts (GBEE) on B16 melanoma bearing mice and its related molecular mechanisms. The B16-F10 melanoma solid tumor model was established in C57BL/6J mice. The tumor-bearing mice were treated with GBEE (50, 100, 200 mg/kg), taking cis-Dichlorodiamineplatinum (Ⅱ) (DDP, 3 mg/kg) as positive control and normal saline (NS) as model control. After 17 days of administration, the transplanted tumors was stripped and weighed, and the inhibition rate was calculated. Quantitative Reverse Transcription Polymerase chain reaction (qRT-PCR), Western Blot and immunohistochemistry were applied to detect mRNA and protein levels of related factors in B16 transplanted tumor tissues. The results indicated that GBEE (50, 100, 200 mg/kg) inhibited the growth of B16 transplanted solid tumor in C57BL/6J mice. Meanwhile, it inhibited the expression of CD34 and reduced microvessel density (MVD) in a dose-dependent manner. Moreover, GBEE dose-dependently down-regulated the mRNA and protein levels of hypoxia inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and vascular endothelial growth factor receptor 2 (VEGFR2). The phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) proteins were not changed obviously, but the protein levels of p-PI3K and p-Akt were down-regulated. Overall, the inhibitory effect of GBEE on the growth of B16 melanoma transplant tumor in mice is related to inhibiting angiogenesis, and the mechanism involves the regulation of PI3K/Akt/ HIF-lα/VEGF signaling pathway.

MiR-15a/16-1 deficiency induces IL-10-producing CD19+ TIM-1+ cells in tumor microenvironment.

IL-10-producing B cells (B10) are associated with autoimmune diseases, infection and tumours. MiR-15a/16 as a tumour-suppressive gene is down-regulated in several tumours, such as chronic lymphocytic leukaemia, pituitary adenomas and prostate carcinoma. Here, increased frequency of IL-10-producing CD19+ Tim-1+ cells was seen in both aged miR-15a/16-/- mice (15-18 months) with the onset of B cell leukaemia and young knockout mice (8-12 weeks) transplanted with hepatic cancer cells. CD19+ Tim-1+ cells down-regulated the function of effector CD4+ CD25low T cells ex vivo dependent on IL-10 production, and adoptive transfer of CD19+ Tim-1+ cells promoted tumour growth in mice. IL-10 production by CD19+ Tim-1+ cells was involved with the STAT3 activation. Bioinformatics analysis shows that miR-16 targets the 3'-untranslating region (3'-UTR) of STAT3 mRNA. Overexpression of miR-16 in CD19+ Tim-1+ cells inhibited STAT3 transcription and its protein expression. Thus, the loss of miR-15a/16 promoted induction of regulatory CD19+ Tim-1+ cells in tumour microenvironment. These results confirmed that miR-15a/16 could be used in tumour therapy due to its inhibition of tumour and regulatory B cells.