Glucuronidation and its effect on the bioactivity of amentoflavone, a biflavonoid from Ginkgo biloba leaves

OBJECTIVES

Ginkgo biloba leaves contain amentoflavone (AMF), a dietary flavonoid that possesses antioxidant and anticancer activity. Flavonoids are extensively subjected to glucuronidation. This study aimed to determine the metabolic profile of AMF and the effect of glucuronidation on AMF bioactivity.

METHODS

A pharmacokinetic study was conducted to determine the plasma concentrations of AMF and its metabolites. The metabolic profile of AMF was elucidated using different species of microsomes. The antioxidant activity of AMF metabolites was determined using DPPH/ABTS radical and nitric oxide assays. The anticancer activity of AMF metabolites was evaluated in U87MG/U251 cells.

KEY FINDINGS

Pharmacokinetic studies indicated that the oral bioavailability of AMF was 0.06 ± 0.04%, and the area under the curve of the glucuronidated AMF metabolites (410.938 ± 62.219 ng/ml h) was significantly higher than that of AMF (194.509 ± 16.915 ng/ml h). UGT1A1 and UGT1A3 greatly metabolized AMF. No significant difference was observed in the antioxidant activity between AMF and its metabolites. The anticancer activity of AMF metabolites significantly decreased.

CONCLUSIONS

A low AMF bioavailability was due to extensive glucuronidation, which was mediated by UGT1A1 and UGT1A3. Glucuronidated AMF metabolites had the same antioxidant but had a lower anticancer activity than that of AMF.

Advanced glycation end products inhibit neural stem cell differentiation via upregualtion of HDAC3 expression

Diabetes mellitus (DM) is a highly prevalent chronic systemic disease, which may cause cognitive decline and degenerative change of the brain. Neuronal differentiation defects of neural stem cells (NSCs) played an important role in the development and progression of diabetes-associated cognitive decline (DACD), but the intrinsic pathological mechanism remains largely unclear. In the present study, we demonstrated that expression level of HDAC3 was upregulated in diabetic mice with reduced learning and memory abilities and in cultured NSCs after advanced glycation end products (AGEs) induction. In addition, AGEs interfered with normal differentiation of the cultured NSCs, and knocking down the expression of HDAC3 could partially attenuate the inhibitory effect of AGEs on NSCs differentiation. Findings in this study demonstrate that HDAC3 may serve as an experimental clue for revealing the pathogenesis of DACD.

Next-generation sequencing of cerebrospinal fluid for the diagnosis of neurocysticercosis

OBJECTIVE

Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system (CNS). However, a diagnosis of NCC may be hard to make if the specific clinical and routine neuroimaging manifestations are lacking, which hinders physicians from considering further immunodiagnostic tests.

PATIENTS AND METHODS

Seven patients presented with fever, headache, nausea, cognitive decline, confusion, or progressive leg weakness. There were no pathogens found in the cerebrospinal fluid (CSF); patients were clinically suspected of meningoencephalitis or cerebrovascular disease. To clearly determine the etiology, next generation sequencing (NGS) of the CSF was used to detect pathogens in these seven patients.

RESULTS

Taenia solium DNA sequences were detected in the seven patients, but not in the non-template controls (NTCs) or the other patients with clinically suspected CNS infections. Based on the patients' medical data and the diagnostic criteria for NCC, seven patients were diagnosed with probable NCC. The unique reads aligning to Taenia solium ranged from 6 to 261064, with genomic coverage ranging from 0.0003% to 14.8079%. The number of unique reads and genomic coverage dropped in three of the seven patients after antiparasitic treatment, consistent with the relief of symptoms.

CONCLUSION

This study showed that NGS of the CSF might be an auxiliary diagnostic method for NCC patients. Larger studies are required.

Molecular cloning and characterization of Y-box gene (Rpybx) from Manila clam and its expression analysis in different strains under low-temperature stress

Manila clam, Ruditapes philippinarum, is an economically important marine bivalve species. Y-box proteins are members of the cold shock proteins family and highly conserved from bacteria to humans. In this study, a novel Y-box gene (Rpybx) was cloned from the Manila clam and gene expression profiling was performed on three shell color strains (white, zebra and white zebra) and two wild populations (Southern and Northern) of R. philippinarum. The complete ORF length of Rpybx is 1367 bp, encoding 253 amino acids residues. Based on the amino acid sequence analysis and phylogenetic analysis, the Rpybx gene was identified as a member of the invertebrate Y-box proteins family. Rpybx has a similar tertiary structure to human Y-box protein YB-1. The Rpybx mRNA levels were analyzed by qPCR under acute and gradually varied cold stress. Under acute low-temperature stress, the expression of Rpybx mRNA in gills and hepatopancreas was significantly increased in all selected strains and populations (P < 0.05). The Northern population showed the lowest relative expression level of Rpybx. The expressions of Rpybx were greatly upregulated in gills and hepatopancreas of different stains and populations at 5 or -2°C under gradually varied temperature stress (P < 0.05). The results shed light on the biological function of the Rpybx gene in defending against low-temperature challenge and further exploring the molecular mechanism of cold tolerance and resistance in R. philippinarum.

Versatile cationic liposomes for RIP3 overexpression in colon cancer therapy and RIP3 downregulation in acute pancreatitis therapy

Because the induction of strong host antitumor responses plays a very important role in antitumor therapy, identifying effective approaches to elicit immunogenic cell death could have important implications. RIP3-dependent necroptotic cancer cells have been reported to release damage-associated molecular patterns and enhance antitumor immunity. In this study, hyaluronic acid-conjugated cationic liposomes (DOTAP/DOPE/PEG-DSPE/CHOL) (HA-P-LP) were prepared as a vector for mRIP3-pDNA overexpression in tumours. Compared with standard cationic liposomes, this vector markedly increased cellular gene internalisation in vitro, enhanced the tumour-targeting effect in vivo and exhibited a significant antitumor effect in combination with adjuvant chloroquine. Considering the dramatic increase in RIP3 under the pathological condition of pancreatitis and the correlation between pancreatitis and necroptosis, non-HA-conjugated liposomes with the same formulation loaded with shRNA mRIP3-pDNA effectively controlled the disease by decreasing the serum amylase concentration and inflammatory cell infiltration. The versatile cationic liposomes loaded with plasmids with opposing functions in this study provide a new concept and method for both tumour therapy and pancreatitis therapy.

pH-sensitive CAP/SiO2 composite for efficient co-delivery of doxorubicin and siRNA to overcome multiple drug resistance

CAP/SiO₂ composite with good biocompatibility and acid biodegradability has been prepared. The proposed drug and gene codelivery system based on it demonstrated enhanced therapeutic efficacy for multiple drug resistance cells.

Local Learning Approaches for Finding Effects of a Specified Cause and Their Causal Paths

Causal networks are used to describe and to discover causal relationships among variables and data generating mechanisms. There have been many approaches for learning a global causal network of all observed variables. In many applications, we may be interested in finding what are the effects of a specified cause variable and what are the causal paths from the cause variable to its effects. Instead of learning a global causal network, we propose several local learning approaches for finding all effects (or descendants) of the specified cause variable and the causal paths from the cause variable to some effect variable of interest. We discuss the identifiability of the effects and the causal paths from observed data and prior knowledge. For the case that the causal paths are not identifiable, our approaches try to find a path set that contains the causal paths of interest.

An Antioxidant Role by Minocycline Via Enhancing the Activation of LKB1/AMPK Signaling in the Process of Cerebral Ischemia Injury

BACKGROUND

LKB1/AMPK signaling pathway, as a metabolic checkpoint, is involved in the pathogenesis of cerebral ischemia injury. Minocycline, a tetracycline derivative, protects against cerebral ischemia via reducing inflammation, oxidative stress, and apoptosis. The aim of the study was to evaluate the influence of minocycline on oxidative biomarkers and LKB1/AMPK signaling pathway in Wistar rats with focal cerebral ischemia injury and to clarify the neuroprotective mechanism of minocycline against focal cerebral ischemia injury.

METHODS

The focal cerebral ischemia injury of Wistar rats was established by inserting a thread into the left middle cerebral artery. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to label infarct volume. The levels of MDA and LPO were measured with a biochemical assay. All other items were determined by Western blotting.

RESULTS

Minocycline decreased cerebral infarct volume, but had no effects on neurological scores. Minocycline improved the biological activity of GPx-1/2, GSS and GR, while limited the GGT1 activity in the hippocampus of cerebral ischemia-reperfusion rats. Minocycline also elevated the biological activity of SOD and counteracted lipid peroxidation. Minocycline enhanced the activity of both LKB1 and the levels of the three AMPK subunits in the hippocampus of cerebral ischemia-reperfusion rats.

CONCLUSION

Minocycline effectively inhibits oxidative stress via modulating antioxidative enzymes and activating the LKB1/AMPK signaling pathway in the process of acute cerebral infarct.

T Cell Receptor Immune Repertoires Are Promptly Reconstituted After Methicillin-Resistant Staphylococcus aureus Infection

T cells represent a subset of lymphocytes characterized by immunosurveillance and immunoregulation function. Peripheral blood mononuclear cells (PBMCs) are enriched in T cells, which exert critical antimicrobial roles in infectious diseases. High-throughput sequencing of the T cell receptor (TCR) provides deep insight into monitoring the immune microenvironment. Flow cytometry was used to analyse the distribution of αβ/γδ T cells and their CD69, IFN-γ/IL-17 expression from PBMCs. Here, we utilized next-generation sequencing (NGS) to detect the complementarity determining region 3 (CDR3) of TCRβ (TRB) and TCRδ (TRD) chain after methicillin-resistant Staphylococcus aureus (MRSA) infection. Our data demonstrated a significant increase in the activation of αβ and γδ T cells after MRSA infection. Simultaneously, significantly high CDR3 amino acid (AA) diversity and markedly reconstituted TCR immune repertoires were observed after MRSA infection. Finally, we identified several MRSA-specific initial CDR3 AA motifs after MRSA infection. Our work reveals the profiles of TRB and TRD immune repertoires in response to MRSA and demonstrates a reconstitution of the TCR immune repertoire after MRSA infection.

Recent Advance in Polymer Based Microspheric Systems for Controlled Protein and Peptide Delivery

Sustained-release systems made by biodegradable polymers for protein and peptide drug delivery have received considerable attention by academic researchers and major pharmaceutical companies around the world. Various types of biodegradable materials, including natural and synthetic polymers, have been applied to form protein and peptide drug carriers. Among these material candidates, poly lactic acid (PLA) and poly lactic-co-glycolic acid (PLGA) are the most commonly used biodegradable materials in the development of protein and peptide microspheres. In addition, many microsphere preparation technologies, including spray drying, coacervation, multiple emulsion solvent evaporation method and microporous membrane emulsification have been developed for microspheres preparation. In this review, we particularly summarize and briefly introduce the materials and methods that are used to fabricate microspheres as protein delivery systems. The existing opportunities and challenges for successful protein delivery are also discussed.

A novel macrophage-mediated biomimetic delivery system with NIR-triggered release for prostate cancer therapy

Background

Macrophages with tumor-tropic migratory properties can serve as a cellular carrier to enhance the efficacy of anti neoplastic agents. However, limited drug loading (DL) and insufficient drug release at the tumor site remain the main obstacles in developing macrophage-based delivery systems. In this study, we constructed a biomimetic delivery system (BDS) by loading doxorubicin (DOX)-loaded reduced graphene oxide (rGO) into a mouse macrophage-like cell line (RAW264.7), hoping that the newly constructed BDS could perfectly combine the tumor-tropic ability of macrophages and the photothermal property of rGO.

Results

At the same DOX concentration, the macrophages could absorb more DOX/PEG-BPEI-rGO than free DOX. The tumor-tropic capacity of RAW264.7 cells towards RM-1 mouse prostate cancer cells did not undergo significant change after drug loading in vitro and in vivo. PEG-BPEI-rGO encapsulated in the macrophages could effectively convert the absorbed near-infrared light into heat energy, causing rapid release of DOX. The BDS showed excellent anti-tumor efficacy in vivo.

Conclusions

The BDS that we developed in this study had the following characteristic features: active targeting of tumor cells, stimuli-release triggered by near-infrared laser (NIR), and effective combination of chemotherapy and photothermotherapy. Using the photothermal effect produced by PEG-BPEI-rGO and DOX released from the macrophages upon NIR irradiation, MAs-DOX/PEG-BPEI-rGO exhibited a significant inhibitory effect on tumor growth.

Identification of critical pathways and hub genes in TP53 mutation prostate cancer by bioinformatics analysis

Aim: The TP53 mutant is one of the most common mutant genes in prostate cancer. Materials & methods: The RNA-seq data of prostate cancer was downloaded from TCGA database. Gene set and enrichment analyses were done by online tools. Results: TP53 mutation was found in 18% prostate cancer patients. Enrichment analysis indicated that differentially expressed genes were enriched in GPCR signaling pathways, cell growth and metabolism. The top ten hub genes were identified. Further analysis showed increased risk of recurrence, lower TP53 mRNA level and higher Gleason scores in patients with TP53 mutation. Conclusion: Our results suggest that multiple genes and pathways may play key roles in TP53 mutant prostate cancer, providing candidate targets and strategies for individualized treatment.

iRGD-Mediated and Enzyme-Induced Precise Targeting and Retention of Gold Nanoparticles for the Enhanced Imaging and Treatment of Breast Cancer

Despite the great achievements of nanomedicines made in cancer chemotherapy, precise tumor targeting and deep penetration are still major challenges. Many nanomedicines can only passively accumulate near leaky site of tumor vessels through the enhanced permeability and retention (EPR) effect and cannot reach the deep region of tumor. To improve the tumor targeting, penetration and retention efficiency, an iRGD-mediated and enzyme-induced precise targeting gold nanoparticles system (iRGD/AuNPs-A&C) was developed by simply coadministering a tumor-homing penetration peptide iRGD (CRGDKGPDC) with a legumain responsive aggregable gold nanoparticle (AuNPs-A&C). In vitro, iRGD/AuNPs-A&C showed a consistent increase rate in size with AuNPs-A&C, suggesting that iRGD/AuNPs-A&C could also aggregate in the presence of legumain, which was in favor of the enhanced retention in tumor microenvironment. Meanwhile, iRGD/AuNPs-A&C showed higher 4T1 cells cellular uptake in vitro and presented higher penetration and accumulation in breast tumor in vivo than AuNPs-A&C, leading to enhanced tumor imaging efficacy and the improved chemotherapeutic effect to 4T1-bearing mice. These results suggested that the iRGD-mediated and enzyme-induced dual-functional nanoplatform was promising for the 4T1 tumor imaging and treatment.

Comparison of the gut microbiota composition between the wild and captive Tibetan wild ass (Equus kiang)

Aims

The gut microbiota has a great effect on the health and nutrition of the host. Manipulation of the intestinal microbiota may improve animal health and growth performance. The objectives of our study were to characterize the faecal microbiota between wild and captive Tibetan wild asses and discuss the differences and their reasons.

Methods and Results

Through high‐throughput sequencing of the 16S rRNA V4‐V5 region, we studied the gut microbiota composition and structure of Tibetan wild asses in winter, and analysed the differences between wild and captive groups. The results showed that the most common bacterial phylum in Tibetan wild ass faeces samples was Bacteroidetes, while the phylum Firmicutes was dominant in captive Tibetan wild ass faecal samples. The relative abundance of Firmicutes, Tenericutes and Spirochaetes were significantly higher (P < 0·01) than in the wild groups.

Conclusions

Captivity reduces intestinal microbial diversity, evenness and operational taxonomic unit number due to the consumption of industrial food, therefore, increasing the risk of disease prevalence and affecting the health of wildlife.

Significance and Impact of the Study

We studied the effect of the captive environment on intestinal micro‐organisms. This article provides a theoretical basis for the ex‐situ conservation of wild animals in the future.

[Application of pegylated recombinant human granulocyte colony-stimulating factor to prevent chemotherapy-induced neutropenia in patients with lymphoma: a prospective, multicenter, open-label clinical trial]

目的

评价聚乙二醇化重组人粒细胞刺激因子（PEG-rhG-CSF）预防淋巴瘤患者化疗后发生中性粒细胞减少症的有效性和安全性。

方法

本研究为多中心、开放、单臂、Ⅳ期临床试验。纳入410例淋巴瘤患者接受多周期化疗并预防性使用PEG-rhG-CSF。主要观察患者各化疗周期Ⅲ/Ⅳ度中性粒细胞减少症和发热性中性粒细胞减少（FN）的发生率，同时观察患者整个化疗期间抗生素的使用率。

结果

①410例患者中，违背入选标准8例（1.95%），失访35例（8.54%），发生不良事件19例（4.63%），出现符合终止研究标准者12例（2.93%），疾病进展或复发15例（3.66%），故最终321例（78.29%）进入符合方案集。②在第1~4个治疗周期，初级预防给予PEG-rhG-CSF后，Ⅳ度中性粒细胞减少症的发生率分别为19.14%（49/256）、12.50%（32/256）、12.18%（24/197）、13.61%（20/147），FN的发生率分别为3.52%（9/256）、0.39%（1/256）、2.54%（5/197）、2.04%（3/147）；次级预防给药后，Ⅳ度中性粒细胞减少症的发生率从61.54%（40/65）降至16.92%（11/65）、18.46%（12/65）、20.75%（11/53），FN的发生率从16.92%（11/65）降至1.54%（1/65）、4.62%（3/65）、3.77%（2/53）。③整个化疗期间接受抗生素治疗的受试者比例为34.39%（141/410）。④与PEG-rhG-CSF相关的不良事件发生率为4.63%（19/410），最常见的不良反应为骨痛[3.90%（16/410）]、乏力（0.49%）和发热（0.24%）。

结论

在淋巴瘤患者化疗过程中，预防性使用PEG-rhG-CSF能够有效降低化疗过程中Ⅲ/Ⅳ度中性粒细胞减少症和FN的发生率，确保淋巴瘤患者接受标准剂量化疗，提高治愈率。