Atorvastatin improved ulcerative colitis in association with gut microbiota-derived tryptophan metabolism.

AIMS: Atorvastatin is a commonly used cholesterol-lowering drug that possesses non-canonical anti-inflammatory properties. However, the precise mechanism underlying its anti-inflammatory effects remains unclear. MATERIALS AND METHODS: The acute phase of ulcerative colitis (UC) was induced using a 5 % dextran sulfate sodium (DSS) solution for 7 consecutive days and administrated with atorvastatin (10 mg/kg) from day 3 to day 7. mRNA-seq, histological pathology, and inflammatory response were determined. Intestinal microbiota alteration, tryptophan, and its metabolites were analyzed through 16S rRNA sequencing and untargeted metabolomics. KEY FINDINGS: Atorvastatin relieved the DSS-induced UC in mice, as evidenced by colon length, body weight, disease activity index score and pathological staining. Atorvastatin treatment reduced the level of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). Atorvastatin also relieved the intestinal microbiota disorder caused by UC and decreased the proliferation of pernicious microbiota such as Akkermansia and Bacteroides. Atorvastatin dramatically altered tryptophan metabolism and increased the fecal contents of tryptophan, indolelactic acid (ILA), and indole-3-acetic acid (IAA). Furthermore, atorvastatin enhanced the expression level of aryl hydrocarbon receptor (AhR) and interleukin-22 (IL-22) and further promoted the expression level of intestinal tight junction proteins, such as ZO-1 and occludin, in colitis mice. SIGNIFICANCE: These findings indicated that atorvastatin could alleviate UC by regulating intestinal flora disorders, promoting microbial tryptophan metabolism, and repairing the intestinal barrier.

Construction and Comprehensive Analysis of ceRNA Networks and Tumor-Infiltrating Immune Cells in Hepatocellular Carcinoma With Vascular Invasion.

Background: Hepatocellular carcinoma (HCC) is a common malignant cancer. Metastasis plays a critical role in tumor progression, and vascular invasion is considered one of the most crucial factors for HCC metastasis. However, comprehensive analysis focusing on competitive endogenous RNA (ceRNA) and immune infiltration in the vascular invasion of HCC is lacking. Methods: The gene expression profiles of 321 samples, including 210 primary HCC cases and 111 HCC cases with vascular invasion, were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma project, and used in identifying significant differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs). The RNAs associated with vascular invasion were used in constructing a ceRNA network. A multigene-based risk signature was constructed using the least absolute shrinkage and selection operator algorithm. We detected the fractions of 28 immune cell types in HCC through single-sample gene set enrichment analysis (ssGSEA). Finally, the relationship between the ceRNA network and immune cells was determined through correlation analysis and used in clarifying the potential mechanism involved in vascular invasion. Results: Overall, 413 DElncRNAs, 27 DEmiRNAs, and 397 DEmRNAs were recognized in HCC. A specific ceRNA network based on the interaction among 3 lncRNA-miRNA pairs and 24 miRNA-mRNA pairs were established. A ceRNA-based prognostic signature was constructed and used in dividing samples into high- and low-risk subgroups. The signature showed significant efficacy; its 3- and 5-year areas under the receiver operating characteristic curves were 0.712 and 0.653, respectively. ceRNA and ssGSEA integration analysis demonstrated that PART1 (p = 0, R = -0.33) and CDK5R2 (p = 0.01, R = -0.15) were negatively correlated to natural killer cells. Conclusion: This study demonstrated that vascular invasion in HCC might be related to PART1, and its role in regulating CDK5R2 and NK cells. A nomogram was developed to predict the prognosis of patients with HCC and demonstrated the value of the ceRNA network and tumor-infiltrating immune cells value in improving personalized management.

Corrigendum: YY1 Promotes Endothelial Cell-Dependent Tumor Angiogenesis in Hepatocellular Carcinoma by Transcriptionally Activating VEGFA.

[This corrects the article DOI: 10.3389/fonc.2019.01187.].

Knockdown of THOC1 reduces the proliferation of hepatocellular carcinoma and increases the sensitivity to cisplatin.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant cancers with poor prognosis and high incidence. The clinical data analysis of liver hepatocellular carcinoma samples downloaded from The Cancer Genome Atlas reveals that the THO Complex 1 (THOC1) is remarkable upregulated in HCC and associated with poor prognosis. However, the underlying mechanism remains to be elucidated. We hypothesize that THOC1 can promote the proliferation of HCC. The present study aims to identify THOC1 as the target for HCC treatment and broaden our sights into therapeutic strategy for this disease. METHODS: Quantitative RT-PCR, Western blot, immunofluorescence and immunohistochemistry were used to measure gene and protein expression. Colony formation and cell cycle analysis were performed to evaluate the proliferation. The gene set enrichment analysis were performed to identify the function which THOC1 was involved in. The effects of THOC1 on the malignant phenotypes of hepatocellular cells were examined in vitro and in vivo. RESULTS: The gene set enrichment analysis reveals that THOC1 can promote the proliferation and G2/M cell cycle transition of HCC. Similarly, experimental results demonstrate that THOC1 promotes HCC cell proliferation and cell cycle progression. The knockdown of THOC1 leads to R-loop formation and DNA damage and confers sensitivity to cisplatin. In addition, in vivo data demonstrate that THOC1 can enhance tumorigenesis by increasing tumor cell proliferation. Furthermore, virtual screening predicts that THOC1 as a direct target of luteolin. Luteolin can induce DNA damage and suppress the proliferation of HCC by targeting THOC1. Furthermore, the inhibition of THOC1 activity by luteolin enhances the chemosensitivity of HCC tumor cells to cisplatin. CONCLUSIONS: THOC1 was identified as a predictive biomarker vital for HCC-targeted treatments and improvement of clinical prognosis. Luteolin combined with cisplatin can effectively suppress HCC tumor growth, indicating a potential and effective therapeutic strategy that uses luteolin in combination with conventional cytotoxic agents for HCC treatment.

YY1 Promotes Endothelial Cell-Dependent Tumor Angiogenesis in Hepatocellular Carcinoma by Transcriptionally Activating VEGFA.

Hepatocellular carcinoma (HCC) is a typical hypervascular solid tumor that requires neoangiogenesis for growth. The vascular endothelial growth factor (VEGF) is the most potent proangiogenic factor in neovascularization. The multifunctional Yin-Yang 1 (YY1) is involved in the regulation of tumor malignancy of HCC. However, the relationship between YY1 and endothelial cell-dependent tumor angiogenesis in HCC remains unclear. In this study, we observed that YY1 is positively correlated with microvessel density (MVD) and poor prognosis in HCC tissues. We further found that YY1 promotes the transcriptional activity of VEGFA by binding its promoter in HCC. The secreted VEGFA from HCC cells activates phosphorylation of VEGFR2 to promotes tube formation, cell migration, and invasion of vascular endothelial cells in vitro, and promotes tumor growth and angiogenesis in vivo. In addition, upregulation of YY1 enhanced resistance of bevacizumab in HCC cells. These results indicate that YY1 plays essential roles in HCC angiogenesis and resistance of bevacizumab by inducing VEGFA transcription and that YY1 may represent a potential molecular target for antiangiogenic therapy during HCC progression.

Glycyrrhizic Acid-Induced Differentiation Repressed Stemness in Hepatocellular Carcinoma by Targeting c-Jun N-Terminal Kinase 1.

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers with poor prognosis and high incidence. Cancer stem cells play a vital role in tumor initiation and malignancy. The degree of differentiation of HCC is closely related to its stemness. Glycyrrhizic acid (GA) plays a critical role in inhibiting the degree of malignancy of HCC. At present, the effect of GA on the differentiation and stemness of HCC has not been reported, and its pharmacological mechanism remains to be elucidated. This study evaluated the effect of GA on the stemness of HCC and investigated its targets through proteomics and chemical biology. Results showed that GA can repress stemness and induce differentiation in HCC in vitro. GEO analysis revealed that cell differentiation and stem cell pluripotency were up-regulated and down-regulated after GA administration, respectively. Virtual screening was used to predict the c-Jun N-terminal kinase 1 (JNK1) as a direct target of GA. Moreover, chemical biology was used to verify the interaction of JNK1 and GA. Experimental data further indicated that JNK1 inhibits stemness and induces differentiation of HCC. GA exerts its function by targeting JNK1. Clinical data analysis from The Cancer Genome Atlas also revealed that JNK1 can aggravate the degree of malignancy of HCC. The results indicated that, by targeting JNK1, GA can inhibit tumor growth through inducing differentiation and repressing stemness. Furthermore, GA enhanced the anti-tumor effects of sorafenib in HCC treatment. These results broadened our insight into the pharmacological mechanism of GA and the importance of JNK1 as a therapeutic target for HCC treatment.

Knockout of zebrafish interleukin 7 receptor (IL7R) by the CRISPR/Cas9 system delays retinal neurodevelopment.

Interleukin 7 receptor (il7r), a transmembrane receptor, belongs to the type I cytokine receptor family. Il7r is involved in the pathogenesis of neurodegenerative disorders, such as multiple sclerosis. Targeted knockdown of il7r leads to delayed myelination, highlighting the potential role of il7r in the development of the nervous system. Zebrafish is an ideal model for the study of neurogenesis; moreover, the il7r gene is highly conserved between zebrafish and human. The aim of the present study was to investigate the novel function of il7r in neurogenesis. First, an il7r -/- homozygous mutant line was generated by clustered regularly interspaced short palindromic repeats (CRISPR)-associated 9 (CRISPR/Cas9) technology. Second, the gross development of il7r-/- mutants revealed remarkably smaller eyes and delayed retinal neurodifferentiation. Third, microarray analysis revealed that genes associated with the phototransduction signalling pathway were strongly down-regulated in il7r -/- mutants. Finally, the results from behavioural tests indicated that visual function was impaired in il7r -/- mutant larvae. Overall, our data demonstrate that a lack of il7r retards the development of the retina. Thus, il7r is an essential molecule for maintaining normal retinal development in zebrafish.

Correlation between photoreceptor injury-regeneration and behavior in a zebrafish model.

Direct exposure to intensive visible light can lead to solar retinopathy, including macular injury. The signs and symptoms include central scotoma, metamorphopsia, and decreased vision. However, there have been few studies examining retinal injury due to intensive light stimulation at the cellular level. Neural network arrangements and gene expression patterns in zebrafish photoreceptors are similar to those observed in humans, and photoreceptor injury in zebrafish can induce stem cell-based cellular regeneration. Therefore, the zebrafish retina is considered a useful model for studying photoreceptor injury in humans. In the current study, the central retinal photoreceptors of zebrafish were selectively ablated by stimulation with high-intensity light. Retinal injury, cell proliferation and regeneration of cones and rods were assessed at 1, 3 and 7 days post lesion with immunohistochemistry and in situ hybridization. Additionally, a light/dark box test was used to assess zebrafish behavior. The results revealed that photoreceptors were regenerated by 7 days after the light-induced injury. However, the regenerated cells showed a disrupted arrangement at the lesion site. During the injury-regeneration process, the zebrafish exhibited reduced locomotor capacity, weakened phototaxis and increased movement angular velocity. These behaviors matched the morphological changes of retinal injury and regeneration in a number of ways. This study demonstrates that the zebrafish retina has a robust capacity for regeneration. Visual impairment and stress responses following high-intensity light stimulation appear to contribute to the alteration of behaviors.

Down-regulation of interleukin 7 receptor (IL-7R) contributes to central nervous system demyelination.

Interleukin 7 receptor (IL-7R) has been associated with the pathogenesis of multiple sclerosis (MS), though the mechanisms are not clear. Because myelin expression is highly conserved between zebrafish and mammals, zebrafish have become an ideal model for studying demyelination. We used a transgenic (Tg; mbp:nfsB-egfp) zebrafish line in which oligodendrocytes expressed green fluorescent protein (GFP) from the larval stage to adulthood. Exposing adult transgenic zebrafish to metronidazole induced demyelination that resembled the morphological changes associated with the early stages of MS. The metronidazole-induced demyelination was confirmed by magnetic resonance imaging (MRI) for the first time. Microarray analysis revealed down-regulation of IL-7R during demyelination. Targeted knockdown of IL-7R demonstrated that IL-7R is essential for myelination in embryonic and larval zebrafish. Moreover, IL-7R down-regulation induced signaling via the JAK/STAT pathway leading to apoptosis in oligodendrocytes. These findings contribute to our understanding of the role of IL-7R in demyelination, and provide a rationale for the development of IL-7R-based therapies for MS and other demyelinating diseases.

Fluorescent Imaging-Guided Chemotherapy-and-Photodynamic Dual Therapy with Nanoscale Porphyrin Metal-Organic Framework.

Imaging-guided therapy systems (IGTSs) are revolutionary techniques used in cancer treatment due to their safety and efficiency. IGTSs should have tunable compositions for bioimaging, a suitable size and shape for biotransfer, sufficient channels and/or pores for drug loading, and intrinsic biocompatibility. Here, a biocompatible nanoscale zirconium-porphyrin metal-organic framework (NPMOF)-based IGTS that is prepared using a microemulsion strategy and carefully tuned reaction conditions is reported. A high content of porphyrin (59.8%) allows the achievement of efficient fluorescent imaging and photodynamic therapy (PDT). The 1D channel of the Kagome topology of NPMOFs provides a 109% doxorubicin loading and pH-response smart release for chemotherapy. The fluorescence guiding of the chemotherapy-and-PDT dual system is confirmed by the concentration of NPMOFs at cancer sites after irradiation with a laser and doxorubicin release, while low toxicity is observed in normal tissues. NPMOFs are established as a promising platform for the early diagnosis of cancer and initial therapy.

One-Pot Microwave Synthesis of Water-Dispersible, High Fluorescence Silicon Nanoparticles and Their Imaging Applications in Vitro and in Vivo.

Silicon nanoparticles (SiNPs) have been reported to be synthesized by microwave-assisted methods under high pressure. However, there is still a lack of knowledge about the synthesis of SiNPs via microwave-assisted methods under normal pressure. Here we developed a new, facile, one-pot microwave-assisted method for the synthesis SiNPs (∼4.2 nm) with excellent water solubility under normal pressure by employing glycerol as the solvent. Furthermore, glycerol might be responsible for the photoluminescence quantum yield (PLQY) value up to 47% for the resultant SiNPs. The use of organic solvent could afford less nanoparticle surface defects compared with those prepared in aqueous solution, thus improving the fluorescent efficiency. The as-prepared SiNPs simultaneously featured bright blue-green fluorescence, long lifetime (∼12.8 ns), obvious up-conversion luminescence originating from two-photon absorption, superbly strong photostability, and favorable low toxicity. As a satisfactory probe, the as-synthesized SiNPs were successfully applied in fluorescence imaging of human cervical carcinoma cell lines (HeLa) and zebrafish.

Role of tumor necrosis factor-alpha in zebrafish retinal neurogenesis and myelination.

AIM: To investigate the role of tumor necrosis factor-alpha (TNF-α) in zebrafish retinal development and myelination. METHODS: Morpholino oligonucleotides (MO), which are complementary to the translation start site of the wild-type embryonic zebrafish TNF-α mRNA sequence, were synthesized and injected into one- to four-cell embryos. The translation blocking specificity was verified by Western blotting using an anti-TNF-α antibody, whole-mount in situ hybridization using a hepatocyte-specific mRNA probe ceruloplasmin (cp), and co-injection of TNF-α MO and TNF-α mRNA. An atonal homolog 7 (atoh7) mRNA probe was used to detect neurogenesis onset. The retinal neurodifferentiation was analyzed by immunohistochemistry using antibodies Zn12, Zpr1, and Zpr3 to label ganglion cells, cones, and rods, respectively. Myelin basic protein (mbp) was used as a marker to track and observe the myelination using whole-mount in situ hybridization. RESULTS: Targeted knockdown of TNF-α resulted in specific suppression of TNF-α expression and a severely underdeveloped liver. The co-injection of TNF-α MO and mRNA rescued the liver development. Retinal neurogenesis in TNF-α morphants was initiated on time. The retina was fully laminated, while ganglion cells, cones, and rods were well differentiated at 72 hours post-fertilization (hpf). mbp was expressed in Schwann cells in the lateral line nerves and cranial nerves from 3 days post-fertilization (dpf) as well as in oligodendrocytes linearly along the hindbrain bundles and the spinal cord from 4 dpf, which closely resembled its endogenous profile. CONCLUSION: TNF-α is not an essential regulator for retinal neurogenesis and optic myelination.