Pravastatin promotes type 2 diabetes vascular calcification through activating intestinal Bacteroides fragilis to induce macrophage M1 polarization

BACKGROUND

Pravastatin is an oral lipid-lowering drug, commonly used by patients with diabetes that is positively correlated with the occurrence of vascular calcification (VC), but the mechanism is unclear.

METHODS

In this study, 16S rRNA sequencing and qRT-PCR wereused to detect the differential gut bacteria. Metabolomics and ELISA were used to analyze the differential metabolites. qRT-PCR and western blotting (WB) were used to detect genes expression. Flow cytometry was used to analyze macrophage phenotype. Immunohistochemistry was used to analyze aortic calcification.

RESULTS

We found that gut Bacteroides fragilis (BF) increased significantly in patients who took pravastatin or type 2 diabetes (T2D) mice treated with pravastatin. In vitro experiments showed that pravastatin had little effect on BF but significantly promoted BF proliferation in vivo. Further analysis showed that ArsR was an important gene for pravastatin to regulate the activation of BF, and overexpression of ArsR significantly promoted the secretion of 3,4,5-trimethoxycinnamic acid (TMCA). Importantly, pravastatin significantly promoted BF secretion of TMCA and significantly increased TMCA secretion in T2D patients or T2D mice. TMCA had little effect on vascular smooth muscle cell calcification but significantly promoted macrophage M1 polarization, which we had demonstrated that M1 macrophages promoted T2D VC. In vivo studies found that pravastatin significantly upregulated TMCA levels in the feces and serum of T2D mice transplanted with BF and promoted the macrophage M1 polarization in bone marrow and the osteoblastic differentiation of aortic cells. Similar results were obtained in T2D mice after intravenous infusion of TMCA.

CONCLUSIONS

Promoting intestinal BF to secrete TMCA, which leads to macrophage M1 polarization, is an important mechanism by which pravastatin promotes calcification, and the result will be used for the optimization of clinical medication strategies of pravastatin supplying a theoretical basis and experimental basis.

Glutathionylation of a glycolytic enzyme promotes cell death and vigor loss during aging of elm seeds

Seed deterioration during storage is a major problem in agricultural and forestry production and for germplasm conservation. Our previous studies have shown that a mitochondrial outer membrane protein VOLTAGE-DEPENDENT ANION CHANNEL (VDAC) is involved in programmed cell death (PCD)-like viability loss during the controlled deterioration treatment (CDT) of elm (Ulmus pumila L.) seeds, but its underlying mechanism remains unclear. In this study, we demonstrate that the oxidative modification of GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE (GAPDH) is functioned in the gate regulation of VDAC during the CDT of elm seeds. Through biochemical and cytological methods and observations of transgenic material [Arabidopsis (Arabidopsis thaliana), Nicotiana benthamiana, and yeast (Saccharomyces cerevisiae)], we demonstrate that cysteine S-glutathionylated UpGAPDH1 interacts with UpVDAC3 during seed aging, which leads to a mitochondrial permeability transition and aggravation of cell death, as indicated by the leakage of the mitochondrial pro-apoptotic factor cytochrome c and the emergence of apoptotic nucleus. Physiological assays and inductively coupled plasma mass spectrometry (ICP-MS) analysis revealed that GAPDH glutathionylation is mediated by increased glutathione, which might be caused by increases in the concentrations of free metals, especially Zn. Introduction of the Zn-specific chelator TPEN [(N, N, N', N'-Tetrakis (2-pyridylmethyl)ethylenediamine)] significantly delayed seed aging. We conclude that glutathionylated UpGAPDH1 interacts with UpVDAC3 and serves as a pro-apoptotic protein for VDAC-gating regulation and cell death initiation during seed aging.

Neuroimaging research progress of acupuncture treatment for patients with functional dyspepsia

Neuroimaging technology provides objective and visualized research tool to study the mechanisms of acupuncture effects. Building on a systematic review of previous clinical studies on acupuncture treatment for functional dyspepsia using neuroimaging technology, this paper summarizes and synthesizes past researches from 4 aspects： acupoint-specific effects, factors influencing the effects, different physiological responses, and predictive factors for acupuncture efficacy. It suggests that acupuncture treatment for FD involves central integration with disease-targeted (acupuncture treatment can target and regulate abnormal brain functional activity patterns in patients with FD), meridian-specific (stimulation of specific acupuncture points along the stomach meridian can significantly regulate abnormal brain functional activity patterns in FD patients), and dynamic conditional features(the effects of acupuncture treatment for FD are influenced by multiple factors). Lastly, considering the current research status, this paper outlines prospects in terms of research subjects, influencing factors, and result validation, aiming to provide references for future in-depth research.

Early results of the integrative epigenomic-transcriptomic landscape of colorectal adenoma and cancer

BACKGROUND

Aberrant methylation is common during the initiation and progression of colorectal cancer (CRC), and detecting these changes that occur during early adenoma (ADE) formation and CRC progression has clinical value.

AIM

To identify potential DNA methylation markers specific to ADE and CRC.

METHODS

Here, we performed SeqCap targeted bisulfite sequencing and RNA-seq analysis of colorectal ADE and CRC samples to profile the epigenomic-transcriptomic landscape.

RESULTS

Comparing 22 CRC and 25 ADE samples, global methylation was higher in the former, but both showed similar methylation patterns regarding differentially methylated gene positions, chromatin signatures, and repeated elements. High-grade CRC tended to exhibit elevated methylation levels in gene promoter regions compared to those in low-grade CRC. Combined with RNA-seq gene expression data, we identified 14 methylation-regulated differentially expressed genes, of which only AGTR1 and NECAB1 methylation had prognostic significance.

CONCLUSION

Our results suggest that genome-wide alterations in DNA methylation occur during the early stages of CRC and demonstrate the methylation signatures associated with colorectal ADEs and CRC, suggesting prognostic biomarkers for CRC.

[Fabrication and evaluation of composite hydroxyapatite coating on ordered micro-/nanotextured titanium surface]

Objective: To develope a titanium specimen with good osteogenic activity through fabrication of a composite hydroxyapatite coating on ordered micro-/nanotextured titanium surface. Methods: An ordered micro-/nanotextured structure was prepared on the surface of titanium (the control), and then hydroxyapatite was deposited on the as-prepared ordered micro-/nanotextured structure by alternative loop immersion method. The ordered micro-/nanotextured structures before and after hydroxyapatite deposition were denoted as HA and MN, respectively. Surface morphology was observed using a scanning electron microscope. Bone marrow mesenchymal stem cells (BMMSC) were seeded on the surface of three different materials. Cell morphology was observed with a scanning electron microscope. Cell adhesion and cell proliferation were evaluated using 4', 6-diamidino-2-phenylindole staining and cell counting kit-8 assay, respectively. Extracellular matrix mineralization and the expression levels of osteogenesis-related genes were evaluated by alizarin red staining and real-time quantitative PCR, respectively. Each group has three samples in every experiment. Results: After alternative loop immersing, the MN's original microholes (20 μm in diameter) were retained, and the uniform petal-like hydroxyapatite was deposited on the MN's original titania nanotubes (70 nm in diameter). Compared with the control, BMMSC on MN and HA elongated further and intersected along the micron structure with noticeable pseudopodia and pseudoplates, and the trend was more pronounced especially on HA. The number of early adherent cells on HA was remarkably larger than that on the control and MN at each time point (P<0.05). On day 1, the A value of cell proliferation on HA was significantly higher than that on the control and MN (P<0.05). The A value of cell proliferation on HA was significantly lower than that on the control and MN on day 3 (P<0.05). On day 7, the A value of cell proliferation on HA was significantly lower than that on MN (P<0.05), but there was no statistically significant difference in the A value of cell proliferation between HA and the control on day 7 (P>0.05). The Avalue of extracellular matrix mineralization on HA (0.607±0.011) was significantly higher than that on the control and MN (0.268±0.025 and 0.522±0.022, respectively) (t=-0.25, P<0.001; t=-0.34, P<0.001). The expression levels of bone related genes on HA were significantly higher than those on the control and MN (P<0.05). Conclusions: HA could promote the BMMSC adhesion and osteogenic differentiation, support BMMSC proliferation, and demonstrate good osteogenic activity.

Extracellular vesicles of Bacteroides fragilis regulated macrophage polarization through promoted Sema7a expression

Abnormal activation of macrophage and gut Bacteroides fragilis (BF) are the important induction factors in the occurrence of type 2 diabetes (T2D) and vascular complications. However, it remains unknown whether BF involves in macrophage polarization. In this study, we found that BF extracellular vesicles (EV) can be uptaken by macrophage. BF-EV promote macrophage M1/M2 polarization significantly, and increase Sting expression significantly. Bioinformatics analysis found that Sema7a is an important gene involving in macrophage polarization. The expression of Sema7a can be induced by BF-EV and can be inhibited after C-176 treated. The inhibition expression of Sema7a prevent BF-EV to induce macrophage polarization. Further analysis reveals that there is no direct interaction between Sting and Sema7a, but Sgpl1 can interact with Sting or Sema7a. BF-EV promote the expression of Sgpl1, which the phenomenon can be inhibited after C-176 treated. Importantly, overexpression of Sgpl1 reversed the effect of C-176 for Sema7a expression, while inhibit Sema7a expression has limitation influence for Sting and Sgpl1 expression. In conclusion, this study confirms that Sting-Sgpl1-Sema7a is a key mechanism by which BF-EV regulates macrophage polarization.

Culture of cerebrospinal fluid-contacting neurons from neonatal mouse spinal cord

Cerebrospinal fluid-contacting neurons (CSF-cNs) act crucial role in chemosensory and mechanosensory function in spinal cord. Recently, CSF-cNs were found to be an immature neuron and may be involved in spinal cord injury recovery. But how to culture it and explore its function in vitro are not reported in previous research. Here, we first reported culture and identification of CSF-cNs in vitro. We first established a protocol for in vitro culture of CSF-cNs from the cervical spinal cord of mice within 24 h after birth. Polycystic kidney disease 2-like 1 (PKD2L1)⁺ cells were isolated by fluorescence-activated cell sorting and expressed the neuron marker β-tubulin III and CSF-cNs marker GABA. Intriguingly, PKD2L1⁺ cells formed neurosphere and expressed neural stem cell markers Nestin, Sox2 and GFAP. Thus, our research provided culture and isolation of CSF-cNs and this facilitate the investigation the CSF-cNs function in vitro.

The fate and prospects of stem cell therapy in the treatment of hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a leading cause of long-term neurological disability in neonates and adults. Despite emerging advances in supportive care, like the most effective approach, hypothermia, poor prognosis has still been present in current clinical treatment for HIE. Stem cell therapy has been adopted for treating cerebral ischemia in preclinical and clinical trials, displaying its promising therapeutic value. At present, reported treatments for stroke employed stem cells to replace the lost neurons and integrate them into the existing host circuitry, promoting the release of growth factors to support and stimulate endogenous repair processes, etc. In this review, a meaningful overview to numerous studies published up to now was presented by introducing the preclinical and clinical research status of stem cell therapy for cerebral ischemia and hypoxia, discussing potential therapeutic mechanisms of stem cell transplantation for curing HI-induced brain injury, summarizing a series of approaches for marking transplanted cells and existing imaging systems for stem cell labeling and in vivo tracking, and expounding the endogenous regeneration capability of stem cells in the newborn brain when subjected to an HI insult. Additionally, it's promising to combine stem therapy with neuromodulation through specific regulation of neural circuits. The crucial neural circuits across different brain areas related to functional recovery are of great significance for the application of neuromodulation strategies after the occurrence of neonatal hypoxic ischemic encephalopathy (NHIE).

Trilobatin rescues cognitive impairment of Alzheimer's disease by targeting HMGB1 through mediating SIRT3/SOD2 signaling pathway

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive impairment that currently is uncurable. Previous study shows that trilobatin (TLB), a naturally occurring food additive, exerts neuroprotective effect in experimental models of AD. In the present study we investigated the molecular mechanisms underlying the beneficial effect of TLB on experimental models of AD in vivo and in vitro. APP/PS1 transgenic mice were administered TLB (4, 8 mg· kg-1 ·d-1, i.g.) for 3 months; rats were subjected to ICV injection of Aβ25-35, followed by administration of TLB (2.5, 5, 10 mg· kg-1 ·d-1, i.g.) for 14 days. We showed that TLB administration significantly and dose-dependently ameliorated the cognitive deficits in the two AD animal models, assessed in open field test, novel object recognition test, Y-maze test and Morris water maze test. Furthermore, TLB administration dose-dependently inhibited microglia and astrocyte activation in the hippocampus of APP/PS1 transgenic mice accompanied by decreased expression of high-mobility group box 1 (HMGB1), TLR4 and NF-κB. In Aβ25-25-treated BV2 cells, TLB (12.5-50 μM) concentration-dependently increased the cell viability through inhibiting HMGB1/TLR4/NF-κB signaling pathway. HMGB1 overexpression abrogated the beneficial effects of TLB on BV2 cells after Aβ25-35 insults. Molecular docking and surface plasmon resonance assay revealed that TLB directly bound to HMGB1 with a KD value of 8.541×10-4 M. Furthermore, we demonstrated that TLB inhibited Aβ25-35-induced acetylation of HMGB1 through activating SIRT3/SOD2 signaling pathway, thereby restoring redox homeostasis and suppressing neuroinflammation. These results, for the first time, unravel a new property of TLB: rescuing cognitive impairment of AD via targeting HMGB1 and activating SIRT3/SOD2 signaling pathway.

[Analysis and forecast of burden of pancreatic cancer along with attributable risk factors in Asia countries between 1990 and 2019]

Objective: To analyze the disease burden of pancreatic cancer in major Asian countries and forecast the burden of that in China, which helps to provide reference for the prevention and control of pancreatic cancer. Methods: Data on disease burden of pancreatic cancer among global and major Asian countries from on the Global Burden of Disease (GBD) 2019 were collected to describe burden distribution through the absolute numbers or standardized rates of incidence, death and disability adjusted life years (DALY) by year, sex and socio-demographic index. Estimated annual percentage changes (EAPC) was used to assess the trend of standardized rate. The proportion of deaths attributable to risk factors for pancreatic cancer in 2019 was used to compare by age, sex and region. ARIMA model was performed with R language to predict change of age-standardized incidence and death rates of pancreatic cancer from 2020 to 2029. Results: From 1990 to 2019, the standardized incidence rates of pancreatic cancer in China increased from 3.17/100 000 to 5.78/100 000, and the standardized death rate increased from 3.34/100 000 to 5.99/100 000. The increases exceeded other high-income Asia countries. In the past three decades, the standardized incidence, death and DALY rates of pancreatic cancer in global have increased year by year. Among the major countries in Asia, China has the highest growth rate of disease burden (EAPC of standardized incidence rates=2.32%, 95% CI: 2.10%-2.48% and EAPC of standardized death rate=2.25%, 95% CI: 2.03%-2.42%). In addition, incidence and death rates of pancreatic cancer in China are expected to continue on the rise between 2000 and 2029 by ARIMA model. Incidence rate is expected to increase 15.92% and death rate is expected to increase 15.86%. Conclusions: The standardized incidence and death rates of pancreatic cancer in China increase year by year with an increasing trend for the burden of disease. The disease burden of pancreatic cancer is expected to rise due to the increase and aging of the population. Preventive measures should be adopted to decrease the burden of the pancreatic cancer.

Dendrobine-type alkaloids from Dendrobium nobile

Six dendrobine-type alkaloids were isolated from the tubes of Dendrobium nobile by silica gel, Sephadex LH-20 gel column chromatography, and preparative HPLC. Compound 1 is a new alkaloid containing a pair of amide tautomers, whereas compound 2 is a new dendrobine-type alkaloid. By using spectroscopic techniques including 1 D and 2 D NMR, the structures of compounds 1‒6 were identified as N-methoxylcarbonyldendrobine (1), dendronboic acid (2), dendrobine (3), 6-hydroxyldendrobine (4), dendrobine N-oxide (5), and denrine (6). The cytotoxic effects of the isolated compounds on two human tumour cell lines (HCT-116 and SW1990) were evaluated using MTT assay.

Characteristics and functions of glyceraldehyde 3-phosphate dehydrogenase S-nitrosylation during controlled aging of elm and Arabidopsis seeds

Seed aging is the gradual decline in seed vigor, during which programmed cell death (PCD) occurs. The functions of nitric oxide (NO) are exerted through protein S-nitrosylation, a reversible post-translational modification. During seed aging, more than 80 proteins are S-nitrosylated, but the particular role of individual proteins is unknown. Here, we showed that the S-nitrosylation level of glyceraldehyde 3-phosphate dehydrogenase (UpGAPDH) in elm (Ulmus pumila L.) seeds increased after controlled deterioration treatment. UpGAPDH was S-nitrosylated at Cys154 during S-nitrosoglutathione (GSNO) treatment, and its oligomerization was triggered both in vitro and in elm seeds. Interestingly, UpGAPDH interacted with the mitochondrial voltage-dependent anion channel in an S-nitrosylation-dependent way. Some UpGAPDH-green fluorescent protein in Arabidopsis protoplasts co-localized with mitochondria during the GSNO treatment, while the S-nitrosylation-defective UpGAPDH C154S-GFP protein did not. Seeds of oxUpGAPDH lines showed cell death and lost seed vigor rapidly during controlled deterioration treatment-triggered seed aging, while those overexpressing S-nitrosylation-defective UpGAPDH-Cys154 did not. Our results suggest that S-nitrosylation of UpGAPDH may accelerate cell death and seed deterioration during controlled deterioration treatment. These results provide new insights into the effects of UpGAPDH S-nitrosylation on protein interactions and seed aging.

Beta-Glucuronidase Inhibition by Constituents of Mulberry Bark

Intestinal bacterial β-glucuronidases, the key enzymes responsible for the hydrolysis of various glucuronides into free aglycone, have been recognized as key targets for treating various intestinal diseases. This study aimed to investigate the inhibitory effects and mechanisms of the Mulberry bark constituents on E. coli β-glucuronidase (EcGUS), the most abundant β-glucuronidases produced by intestinal bacteria. The results showed that the flavonoids isolated from Mulberry bark could strongly inhibit E. coli β-glucuronidase, with IC₅₀ values ranging from 1.12 µM to 10.63 µM, which were more potent than D-glucaric acid-1,4-lactone. Furthermore, the mode of inhibition of 5 flavonoids with strong E. coli β-glucuronidase inhibitory activity (IC₅₀ ≤ 5 µM) was carefully investigated by a set of kinetic assays and in silico analyses. The results demonstrated that these flavonoids were noncompetitive inhibitors against E. coli β-glucuronidase-catalyzed 4-nitrophenyl β-D-glucuronide hydrolysis, with Ki values of 0.97 µM, 2.71 µM, 3.74 µM, 3.35 µM, and 4.03 µM for morin (1: ), sanggenon C (2: ), kuwanon G (3: ), sanggenol A (4: ), and kuwanon C (5: ), respectively. Additionally, molecular docking simulations showed that all identified flavonoid-type E. coli β-glucuronidase inhibitors could be well-docked into E. coli β-glucuronidase at nonsubstrate binding sites, which were highly consistent with these agents' noncompetitive inhibition mode. Collectively, our findings demonstrated that the flavonoids in Mulberry bark displayed strong E. coli β-glucuronidase inhibition activity, suggesting that Mulberry bark might be a promising dietary supplement for ameliorating β-glucuronidase-mediated intestinal toxicity.

Trilobatin, a Component from Lithocarpus polystachyrus Rehd., Increases Longevity in C. elegans Through Activating SKN1/SIRT3/DAF16 Signaling Pathway

Trilobatin (TLB) is an effective component from Lithocarpus polystachyrus Rehd. Our previous study revealed that TLB protected against oxidative injury in neuronal cells by AMPK/Nrf2/SIRT3 signaling pathway. However, whether TLB can delay aging remains still a mystery. Therefore, the present study was designed to investigate the possible longevity-enhancing effect of TLB, and further to explore its underlying mechanism in Caenorhabditis elegans (C. elegans). The results showed that TLB exerted beneficial effects on C. elegans, as evidenced by survival rate, body movement assay and pharynx-pumping assay. Furthermore, TLB not only significantly decreased ROS and MDA levels, but also increased anti-oxidant enzyme activities including CAT and SOD, as well as its subtypes SOD2 andSOD3, but not affect SOD1 activity, as evidenced by heat and oxidative stress resistance assays. Whereas, the anti-oxidative effects of TLB were almost abolished in SKN1, Sir2.3, and DAF16 mutant C. elegans. Moreover, TLB augmented the fluorescence intensity of DAF16: GFP, SKN1:GFP, GST4:GFP mutants, indicating that TLB increased the contents of SKN1, SIRT3 and DAF16 due to fluorescence intensity of these mutants, which were indicative of these proteins. In addition, TLB markedly increased the protein expressions of SKN1, SIRT3 and DAF16 as evidenced by ELISA assay. However, its longevity-enhancing effect were abolished in DAF16, Sir2.3, SKN1, SOD2, SOD3, and GST4 mutant C. elegans than those of non-TLB treated controls. In conclusion, TLB effectively prolongs lifespan of C. elegans, through regulating redox homeostasis, which is, at least partially, mediated by SKN1/SIRT3/DAF16 signaling pathway.

Endoscopic resections for superficial esophageal squamous cell epithelial neoplasia: focus on histological discrepancies between biopsy and resected specimens

BACKGROUND

Endoscopic resection has been used for high-grade intraepithelial neoplasia (HGIN) and superficial esophageal squamous cell carcinoma (ESCC) with limited risk of lymph node metastasis. However, some of these lesions cannot be accurately diagnosed based on forceps biopsy prior to treatment. In this study we aimed to investigate how to solve this histological discrepancy and avoid over- and under-treatment.

METHODS

The medical records of patients with superficial esophageal squamous cell neoplasia who underwent endoscopic resection at our hospital from January 2012 to December 2019 were reviewed retrospectively. The histological discrepancy between the biopsy and resected specimens was calculated and its association with clinicopathological parameters was analyzed.

RESULTS

A total of 137 lesions from 129 patients were included. The discrepancy rate between forceps biopsy and resected specimens was 45.3% (62/137). Histological discrepancy was associated with the histological category of the biopsy (p < 0.001). In addition, 17 of the 30 (56.7%) biopsies that was diagnosed as indefinite/negative for neoplasia or low-grade intraepithelial neoplasia were upgraded to HGIN or ESCC after resection. The upgrade was due to lesion size ≥ 10 mm (p = 0.002) and type B intrapapillary capillary loops (p < 0.001). Moreover, 34 of the 83 biopsies that were diagnosed with HGIN were upgraded to ESCC after resection, which was related to lesion size (p = 0.001), location (p = 0.018), and pink color sign (p = 0.002).

CONCLUSIONS

Histological discrepancy between forceps biopsy and resected specimens is common in clinical practice. Recognizing the risk factors for each histological category of biopsy may reduce these discrepancies and improve clinical management.

Identification of Pyrrolizidine Alkaloids in Senecio Plants by Liquid Chromatography-Mass Spectrometry

Pyrrolizidine alkaloids (PAs) are considered as the major constituents that cause hepatoxicity in Senecio plants. PAs can be found in about 3%-5% of the world's flowering plants. Nowadays, the identification method of PAs by separation and preparation was too slow and lacked effective power. A rapid method to identify PAs in plants must be developed. Based on the fragmentation regularity, the hepatoxic PAs and nonhepatoxic PAs were characterized by liquid chromatography-mass spectrometry (LC-MS). The detailed structures of PAs in five Senecio plants were identified based on tandem mass spectrometry (MS/MS) spectrum and chemical research information. In the present study, some new fragmentation regularities of PAs have been found, such as product ions at m/z 122, m/z 140 and m/z 124, m/z 142, which have been discovered as the characteristic fragments of lactone and mono-esterase type of saturated PAs, respectively. Moreover, two product ions at m/z 120 and m/z 138 have been reported as the characteristic fragments of unsaturated PAs. Some of them were found in Senecio species for the first time, and some of them may be new nature product or even new compound. Finally, we classified these plants into five categories based on PAs which were identified in the present study; the result corresponded with the classification by morphology. In addition, we have found some constituents that have odd molecular weight number only in Senecio species but not in Ligularia species; the detailed structures of these non-PAs constituents need penetrating study. LC-MS was rapid and sensitive method for detecting and identifying PAs in plants. Pyrrolizidine alkaloids were the toxiferous constituent of Senecio plants. In this study, we found that PAs can be used as the characteristic constituent of Senecio species.

Longitudinal transcriptome analyses show robust T cell immunity during recovery from COVID-19

Understanding the processes of immune regulation in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for improving treatment. Here, we performed longitudinal whole-transcriptome RNA sequencing on peripheral blood mononuclear cell (PBMC) samples from 18 patients with coronavirus disease 2019 (COVID-19) during their treatment, convalescence, and rehabilitation. After analyzing the regulatory networks of differentially expressed messenger RNAs (mRNAs), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) between the different clinical stages, we found that humoral immunity and type I interferon response were significantly downregulated, while robust T-cell activation and differentiation at the whole transcriptome level constituted the main events that occurred during recovery from COVID-19. The formation of this T cell immune response might be driven by the activation of activating protein-1 (AP-1) related signaling pathway and was weakly affected by other clinical features. These findings uncovered the dynamic pattern of immune responses and indicated the key role of T cell immunity in the creation of immune protection against this disease.

Cerebrospinal fluid-contacting neurons affect the expression of endogenous neural progenitor cells and the recovery of neural function after spinal cord injury

OBJECTIVE

To explore the relationship between cerebrospinal fluid-contacting neurons (CSF-cNs) and endogenous neural progenitor cells (ENPCs) and whether CSF-cNs are involved in nerve repair after spinal cord injury (SCI).

METHODS

Cholera toxin B-horseradish peroxidase complex (CB-HRP) and cholera toxin B conjugated with saporin (CB-SAP) were injected into the lateral ventricles of spinal cord injured rats to mark and destroy the CSF-cNs. Then the rats in the experimental group were injured by SCI. Observe the content and co-expression of CSF-cNs and ENPCs in rats of each group, and observe the recovery of motor function after SCI in each group.

RESULTS

After the destruction of CSF-cNs, the number of ENPCs decreased significantly in the long term after the surgery, and the recovery of motor function also deteriorated as compared to the group with intact CSF-cNs. Meanwhile some cells in the spinal cord express both the biological marker of CSF-cNs and ENPCs.

CONCLUSION

This study shows that the population of ENPCs and motor function recovery in SCI rats declined after the destruction of CSF-cNs, suggesting that CSF-cNs affect the ENPCs population and may be involved in the recovery of neural function after SCI.

[The optimal thresholds of the quantitative fecal immunochemical test for opportunistic screening of colorectal neoplasia]

Objective: To investigate the significance of quantitative fecal immunochemical test (FIT) for opportunistic screening of colorectal neoplasia, and to propose the most optimal thresholds to improve the screening level of early colorectal neoplasia. Methods: The opportunistic screening participants were recruited from the Department of Gastroenterology & GI Endoscopy Center of the Seventh Medical Center of PLA General Hospital, and stool sample was collected before colonoscopy and the quantitative FIT was analyzed by OC-MICRO analysator for each patient. We assessed test performance in detecting colorectal neoplasia (advanced adenoma and CRC)with different thresholds on sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: A total of 1 448 objects were enrolled in this study, including 714 male (49.3%)and 734 female (50.7%).All participants were classified according to the result of colonoscopy and pathology, and 242 cases of colorectal neoplasia were found, containing 157 advanced adnoma and 85 colorectal cancer. The FIT threshold increased from 50 μg/L to 200 μg/L, while the positivity rate dropped from 11.5% to 8.6% and the sensitivity in detecting colorectal neoplasia dropped from 47.9% to 38.8%. However, the specificity increased from 96.8% to 98.2% and the positive predictive value increased from 82.3% to 87.0%.The miss rate of colorectal cancer increased from 11.8% (n=10) to 17.6% (n=15) along with the increase in FIT thresholds, but the miss rate of 100 μg/L and 150 μg/L was the same as 12.9% (n=11). Conclusions: Quantitative FIT,which is simple and fast,with the threshold of 100 μg/L for opportunistic screening, has a high sensitivity and specificity for the diagnosis of colorectal neoplasia,and is an important index in screening and diagnosis of colorectal neoplasia.

MicroRNA-608 Promotes Apoptosis in Non-Small Cell Lung Cancer Cells Treated With Doxorubicin Through the Inhibition of TFAP4

Lung cancer is the most commonly diagnosed type of cancer and the leading cause of cancer-associated death worldwide. MicroRNAs (miRNAs) are non-coding single-stranded RNA molecules of ∼20–25 nucleotides in length. Single nucleotide polymorphisms are a class of genetic variation in the human genome, which when present in miRNA genes are associated with the risk of developing cancer. This study aimed to identify whether the miRNA (miR)-608 polymorphism rs4919510 influenced the incidence of lung cancer, and to explore the underlying mechanisms of miR-608 in the pathogenesis of the disease. A total of 37 patients with non-small cell lung cancer (NSCLC) were selected to determine the expression levels of miR-608; 96 NSCLC patients and 136 cancer-free healthy controls were recruited to determine the incidence of miR-608 rs4919510 in lung cancer patients. Additionally, the impact of miR-608 on the expression of predicted target genes, cell migration, viability, proliferation, and apoptosis was also assessed. We found that the presence of miR-608 rs4919510 did not affect the susceptibility of patients to NSCLC or the maturation of miR-608. miR-608 expression levels were found to be downregulated in NSCLC tissues. Furthermore, overexpression of miR-608 promoted doxorubicin-induced apoptosis in NSCLC cell lines A549 and HCC4006 by inhibiting the expression of transcription factor activating enhancer-binding protein 4 (TFAP4), and high expression levels of TFAP4 were observed in NSCLC tissues. Therefore, our results may provide valuable insights for the chemotherapeutical treatment of NSCLC.

Abstract P1-12-07: Prospective 36-month follow-up to determine changes in body mass index and weight among Chinese breast cancer survivors

Background:Anticancer treatment for breast cancer has been associated with weight gain but such observation has mainly been reported in western patients. More recent data in Asian patients have inconsistent findings. Factors including socio-demographic, clinical and lifestyle may be associated with post-diagnosis weight gain. In this prospective cohort study of women with breast cancer, the objectives were to determine the body mass index (BMI) and weight changes over 36 months after initial diagnosis and the factors associated with such changes.

Methods: Chinese women with newly diagnosed early-stage breast cancer were recruited. Individual woman had her weight measured at breast cancer diagnosis (W0), at study entry (W1) and at 36-month follow-up (W2). Body height was measured at W0. We evaluated change in weight and body mass index (BMI) before and after breast cancer diagnosis.Socio-demographic, clinical and lifestyle factors were assessed to identify potential associated factors with weight changes.

Results: A total of 1133 women with breast cancer had detailed weight measurements at the 3 time-points of assessment. The mean age at diagnosis was 52 years. Fifty-four percent were premenopausal at W1. The proportion of patients with stage 0-I, II and III diseases were 35%, 46% and 19%, respectively.

The proportions of patients who were overweight and obese at the three assessment time-points were 21.2% and 28.5% at W0, 19.7% and 26.6% at W1, and 21.7% and 30.9% at W2 assessment, respectively. When compared to W0, the proportions of women who gained weight within 2-5kg at W1 and W2 were 2.4% and 20.6% respectively, that with weight gain of &gt;5kg at W1 and W2 were 0.5% and 10.0% respectively; 6.1% and 19.6% of women had weight loss &gt;2kg at W1 and W2 respectively.

Compared to W0, the median value of weight change was -0.5 kg (range: -11.4, 18.3) at W1 and 0.6 kg (range: -19.6, 20.5) at W2. On multivariate analysis, only BMI at diagnosis were significantly associated with weight change betweenassessments at diagnosis and W2; the median (range) for weight changes for women who were underweight, normal, overweight and obese were respectively 0.9 (-4.8, 7.6), 0.6 (-13.2, 20.5), 0.5 (-11.5, 13.0) and 0.5 (-19.6, 12.6) kg, p &lt;0.001.

Conclusions: In this prospective study of Chinese women with a history of breast cancer who were followed-up over a 36-months' period, the proportions of women with overweight and obese statuses were relatively stable; weight gain was uncommon among Hong Kong women with breast cancer during the same period. These findings are in contrast with studies conducted in the West, where weight gains were more commonly reported.

Funding: World Cancer Research Fund International (Grant Number WCRF 2010/249 and WCRF 2014/1197)

Citation Format: Yeo W, Lei YY, Cheng AC, Kwok CC, Cheung KL, Lee R, Lee IC, He YQ, Ho S. Prospective 36-month follow-up to determine changes in body mass index and weight among Chinese breast cancer survivors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-07.

Clinical Significance of Myeloid Zinc Finger 1 Expression in the Progression of Gastric Tumourigenesis

BACKGROUND/AIMS

To investigate the clinical significance of myeloid zinc finger 1 (MZF1) expression in various gastric mucosal lesions including chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), intestinal metaplasia (IM), dysplasia (DYS) and gastric cancer (GC) in comparison with normal tissues and gastric cell lines.

METHODS

MZF1 protein expression was detected using immunohistochemical staining in 37 CSG, 88 CAG, 77 IM, 51 DYS, 165 GC and 8 normal tissue samples. Quantitative real-time PCR (qRT-PCR) and western blotting were used to detect the level of MZF1 in gastric cell lines, 15 normal tissues and 34 GC samples, as well as 2 groups of paired primary GC and adjacent normal samples.

RESULTS

Reduced MZF1 expression was detected in most GC cells and tissues. Among the gastric tissues consisting of various stages of lesions (normal, CSG, CAG, IM, DYS and GC), MZF1 protein expression was downregulated in precancerous lesions and GC. The data from clinical analyses showed that decreased MZF1 expression was correlated with tumour invasion (p = 0.044), lymph node metastasis (p = 0.048) and poor prognosis of GC patients (p = 0.003). Moreover, MZF1 was identified as an independent prognostic biomarker for GC patients in multivariate Cox regression analysis (p = 0.009).

CONCLUSION

Downregulation of MZF1 was associated with gastric tumourigenesis, which may be a novel early predictive and prognostic biomarker in GC patients.

Equivalent magnetic vector potential model for low-frequency magnetic exposure assessment

In this paper, a novel source model based on a magnetic vector potential for the assessment of induced electric field strength in a human body exposed to the low-frequency (LF) magnetic field of an electrical appliance is presented. The construction of the vector potential model requires only a single-component magnetic field to be measured close to the appliance under test, hence relieving considerable practical measurement effort-the radial basis functions (RBFs) are adopted for the interpolation of discrete measurements; the magnetic vector potential model can then be directly constructed by summing a set of simple algebraic functions of RBF parameters. The vector potentials are then incorporated into numerical calculations as the equivalent source for evaluations of the induced electric field in the human body model. The accuracy and effectiveness of the proposed model are demonstrated by comparing the induced electric field in a human model to that of the full-wave simulation. This study presents a simple and effective approach for modelling the LF magnetic source. The result of this study could simplify the compliance test procedure for assessing an electrical appliance regarding LF magnetic exposure.

Mismatch Repair Protein hMLH1, but not hMSH2, Enhances Estrogen-Induced Apoptosis of Colon Cancer Cells

BACKGROUND

Epidemiological studies suggest a protective role of estrogen against colon carcinogenesis; this effect appears to be dependent on mismatch repair (MMR) status. However, the underlying mechanism remains unclear. This study investigated the role of MMR proteins in apoptosis of colon cancer cells in the presence or absence of estrogen.

METHODS

Two major MMR proteins, human mutL homolog 1 (hMLH1) and mutS homolog 2 (hMSH2), as well as estrogen receptor-β (ERβ), were transiently expressed in either hMLH1-deficient HCT116 cells or hMSH2-deficient LoVo cells. Effects of estradiol on cell viability and apoptosis were assessed. Furthermore, we examined the apoptotic status of epithelial cells in colonic mucosa taken from previous healthy female subjects with menopausal syndrome before and after 6-month hormone replacement therapy (HRT).

RESULTS

In hMLH1-deficient HCT116 cells, re-expression of hMLH1 led to a significantly decreased cell viability and increased apoptosis, which were further enhanced by estradiol, including marked increase of activated caspase-3 and caspase-9, as well as Bax and P53. The effect of hMLH1 overexpression in LoVo cells resulted in a similar increase in apoptosis that was greatly stimulated by estradiol. The enhanced apoptosis by hMLH1 and estradiol was further validated by FACS analyses of Annexin V expression. Re-expression of hMSH2 or overexpression of ERβ in HCT116 cells also enhanced apoptosis; however, the effects were independent of estradiol. Furthermore, studies on healthy menopausal women before and after 6-month HRT demonstrated a significant HRT-mediated upregulation of the hMLH1 expression, with concomitant elevation of caspase-3 and caspase-9 activation in the colonic mucosa.

CONCLUSION

We present the first evidence that hMLH1 and hMSH2 have similar but distinct roles in the apoptosis of colon cancer cells: an increased expression of either one can promote apoptosis, while only the effect of hMLH1 but not hMSH2 is estradiol-dependent. Our data suggest that MMR status should be assessed before hormone replacement therapy or future application of estrogen-based chemoprevention.

Traction using a clip-with-line is a preferred method for trainees in performing esophageal endoscopic submucosal dissection: an animal model study

BACKGROUND

The optimal operative process of esophageal endoscopic submucosal dissection (ESD), especially for the beginners, is not established. In this study, the clip-with-line method, the tunneling method and the conventional method for esophageal ESD were compared in a training course on live pigs.

METHODS

15 trainee endoscopists were randomized into three groups, the clip-with-line method group, the tunneling method group, and the conventional method group. Each trainee performed four esophageal ESDs on live pigs with one of the specified methods, assisted by a senior endoscopist. The procedural time and speed, the en bloc resection rates, adverse events, and self-completion rates were recorded, and learning curves were drawn.

RESULTS

The procedural time in the clip-with-line group was significantly shorter than those in the tunneling and the conventional method group (47.4 ± 9.0 min versus 67.0 ± 15.1 min and 67.0 ± 11.8 min, p = 0.000). The clip-with-line method had the lowest rates of perforation and muscle layer injury among the three methods. The en bloc resection rates and self-completion rates were similar among the three groups. Learning curves analysis showed the clip-with-line method was the easiest one for the trainees to master.

CONCLUSIONS

The clip-with-line method shortened procedural time for trainees, and was associated with lower rates of adverse events. This method is preferred for endoscopists in their learning periods for esophageal ESD.

Predictive Value of Stemness Factor Sox2 in Gastric Cancer Is Associated with Tumor Location and Stage

Cancer stem cells (CSCs) are thought to be the "root" of cancer. Although stemness-related factors ALDH1A1 and Sox2 have been used as markers to identify gastric CSCs, the expression pattern and significance of these factors in gastric cancer have not been sufficiently demonstrated. In this study, the expressions of ALDH1A1 and Sox2 were detected by immunohistochemistry in 122 gastric cancer specimens. And the correlation between Sox2 or ALDH1A1 expression and clinicopathological parameters and overall survival data were analyzed. The positive rate of ALDH1A1 expression was 60%, but there was no significant difference between survival rates of ALDH1A1-positive and ALDH1A1-negative patients. Sox2 was expressed in 42% of specimens and was associated with poor prognosis of patients (P = 0.015). Stratified analysis showed that Sox2 expression correlated with shorter lifespan only in patients with cardiac gastric cancers (P = 0.002) or stage I or II gastric cancers (P = 0.002); but not in patients with non-cardiac cancers (P = 0.556) or stage III or IV gastric cancers (P = 0.121). Analysis on a database cohort validated the correlation between Sox2 expression and poor prognosis in stage II cancer. Also, expression of Sox2 was associated with lymphnode metastasis in patients with cardiac gastric cancer (P = 0.037). A multivariate analysis revealed that Sox2 was an independent prognostic factor in cardiac gastric cancer. Our results indicate that predictive value of Sox2 in gastric cancer is associated with cardiac cancer location and with early cancer stages (I and II).

LECT2 association with macrophage-mediated killing of Helicobacter pylori by activating NF-κB and nitric oxide production

Helicobacter pylori employs unique methods to colonize the stomach, which induces chronic inflammation. It is also able to avoid eradication by macrophages and other immune cells. Leukocyte cell-derived chemotaxin 2 (LECT2), a multi-functional cytokine involved in many pathological conditions, has recently been shown to activate macrophages via the CD209a receptor. Therefore, we aimed to investigate the effects of LECT2 on H. pylori-infected macrophages. Macrophages were treated with recombinant LECT2, and both their ability to kill H. pylori and produce nitric oxide were analyzed. Western blot was performed to determine nuclear translocation and protein phosphorylation of p65, a subunit of nuclear factor (NF)-κB. Transfection experiments were performed to analyze the signaling pathway of LECT2 in macrophages. We found that treatment with LECT2 enhanced H. pylori killing and nitric oxide production in macrophages. In addition, DNA-binding activity and nuclear translocation of p65 were up-regulated by LECT2 treatment. Furthermore, we found that NF-κB activation by LECT2 was mediated by Raf-1 in macrophages, and Raf-1 phosphorylation was specifically altered in response to LECT2. Moreover, LECT2 induced Ser28 phosphorylation in the intracellular domain of CD209a. CD209a Ser28 phosphorylation was required for LECT2-induced Raf-1 and NF-κB activation in RAW264.7 macrophages. Our study showed that the effects of LECT2 on H. pylori killing and nitric oxide production were dependent on CD209a phosphorylation, Raf-1, and NF-κB activation. Together, these results demonstrate for the first time that exposure to LECT2 can modulate specific intracellular mechanisms downstream of CD209a to enhance H. pylori killing and nitric oxide production in macrophages.

Factors for Endoscopic Submucosal Dissection in Early Colorectal Neoplasms: A Single Center Clinical Experience in China

Background/Aims

Early colorectal (CR) neoplasm can be cured by endoscopic submucosal dissection (ESD), but clinical experience and factors associated with complications from ESD for CR neoplasms in China have not been reported.

Methods

Seventy-eight cases of early CR neoplasm treated with endoscopic resection performed between December 2012 and December 2013 at Beijing Military General Hospital were included. Factors associated with ESD complications and procedure times were evaluated.

Results

The en bloc resection rate was 88.5% (69/78), tumor size was 32.1±10.7 mm, and procedure time was 71.8±49.5 minutes. The major complication was perforation, which occurred in 8.97% of the ESD procedures. Multivariate logistic regression analysis indicated that only tumor size (p=0.022) was associated with ESD perforation. Tumor size (p<0.001) and the non-lifting sign (p=0.017) were independent factors for procedure time, and procedure time (p=0.016) was a key factor for en bloc resection. After a median 10 months (range, 4 to 16) of follow-up, no patients had local recurrence.

Conclusions

This study indicated that ESD is an applicable method for large early CR neoplasm in the colon and rectum. Tumor size and the non-lifting sign might be considerable factors for increased complication rate and procedural time of ESD.

Gomisin A is a Novel Isoform-Specific Probe for the Selective Sensing of Human Cytochrome P450 3A4 in Liver Microsomes and Living Cells

Nearly half of prescription medicines are metabolized by human cytochrome P450 (CYP) 3A. CYP3A4 and 3A5 are two major isoforms of human CYP3A and share most of the substrate spectrum. A very limited previous study distinguished the activity of CYP3A4 and CYP3A5, identifying the challenge in predicting CYP3A-mediated drug clearance and drug-drug interaction. In the present study, we introduced gomisin A (GA) with a dibenzocyclooctadiene skeleton as a novel selective probe of CYP3A4. The major metabolite of GA was fully characterized as 8-hydroxylated GA by LC-MS and NMR. CYP3A4 was assigned as the predominant isozyme involved in GA 8-hydroxylation by reaction phenotyping assays, chemical inhibition assays, and correlation studies. GA 8-hydroxylation in both recombinant human CYP3A4 and human liver microsomes followed classic Michaelis-Menten kinetics. The intrinsic clearance values indicated that CYP3A4 contributed 12.8-fold more than CYP3A5 to GA 8-hydroxylation. Molecular docking studies indicated different hydrogen bonds and π-π interactions between CYP3A4 and CYP3A5, which might result in the different catalytic activity for GA 8-hydroxylation. Furthermore, GA exhibited a stronger inhibitory activity towards CYP3A4 than CYP3A5, which further suggested a preferred selectivity of CYP3A4 for the transformation of GA. More importantly, GA has been successfully applied to selectively monitor the modulation of CYP3A4 activities by the inducer rifampin in hepG2 cells, which is consistent with the level change of CYP3A4 mRNA expression. In summary, our results suggested that GA could be used as a novel probe for the selective sensing of CYP3A4 in tissue and cell preparations.

A Mechanism-Based Model for the Prediction of the Metabolic Sites of Steroids Mediated by Cytochrome P450 3A4

Early prediction of xenobiotic metabolism is essential for drug discovery and development. As the most important human drug-metabolizing enzyme, cytochrome P450 3A4 has a large active cavity and metabolizes a broad spectrum of substrates. The poor substrate specificity of CYP3A4 makes it a huge challenge to predict the metabolic site(s) on its substrates. This study aimed to develop a mechanism-based prediction model based on two key parameters, including the binding conformation and the reaction activity of ligands, which could reveal the process of real metabolic reaction(s) and the site(s) of modification. The newly established model was applied to predict the metabolic site(s) of steroids; a class of CYP3A4-preferred substrates. 38 steroids and 12 non-steroids were randomly divided into training and test sets. Two major metabolic reactions, including aliphatic hydroxylation and N-dealkylation, were involved in this study. At least one of the top three predicted metabolic sites was validated by the experimental data. The overall accuracy for the training and test were 82.14% and 86.36%, respectively. In summary, a mechanism-based prediction model was established for the first time, which could be used to predict the metabolic site(s) of CYP3A4 on steroids with high predictive accuracy.

Structural modifications at the C-4 position strongly affect the glucuronidation of 6,7-dihydroxycoumarins

Esculetin (6,7-dihydroxycoumarin) and its C-4 derivatives have multiple pharmacologic activities, but the poor metabolic stability of these catechols has severely restricted their application in the clinic. Glucuronidation plays important roles in catechols elimination, although thus far the effects of structural modifications on the metabolic selectivity and the catalytic efficacy of the human UDP-glucuronosyltransferase (UGT) enzymes remain unclear. This study was aimed at exploring the structure-glucuronidation relationship of esculetin and its C-4 derivatives, including 4-methyl esculetin, 4-phenyl esculetin, and 4-hydroxymethyl esculetin as well as 4-acetic acid esculetin. It was achieved by identifying the main human UGTs responsible for the different reactions and by careful characterization of the reactions kinetics. These catechols, with the exception of 4-acetic acid esculetin, are selectively metabolized to the corresponding 7-O-glucuronides. UGT1A6 and UGT1A9 are the two major UGTs involved in the 7-O-glucuronidation of 4-methyl esculetin and esculetin. UGT1A6 was the major contributor for 7-O-glucuronidation of 4-hydroxymethyl esculetin, and UGT1A9 played a significant role in the 7-O-glucuronidation of 4-phenyl esculetin. The results of the kinetic analyses revealed that the Km values of the compounds, in both UGT1A9 and human liver microsomes, decreased with increasing hydrophobicity of the C-4 substitutions. The outcome of this was that C-4 hydrophobic and hydrophilic groups on 6,7-dihydroxycoumarin exhibited contrasting effects on UGT affinity. All of these findings provide helpful guidance for further structural modification of 6,7-dihydroxycoumarins with improved metabolic stability.

Genetic variations of ISL1 associated with human congenital heart disease in Chinese Han people

Congenital heart disease (CHD) is the most common birth abnormality, but the etiology of CHD is unknown. ISL1 may play a fundamental role in cardiac morphogenesis, and mutations of this gene could cause CHD. To evaluate whether genetic variations of ISL1 are associated with CHD in Chinese Han people, polymerase chain reaction restriction fragment-length polymorphism and SNaPshot were used to examine 9 polymorphisms of ISL1 in 233 patients with CHD as well as 288 healthy controls. We found that one SNP (rs1017) in ISL1 was significantly associated with simple CHD. Genetic variation of ISL1 was confirmed to be associated with the risk of CHD. ISL1 is related to the atrial septal defect group and the ventricular septal defect group, and the genotypes were associated with the occurrence of CHD in the dominant mode of inheritance. We concluded that rs1017 contributed to the risk of CHD in Chinese Han people, and ISL1 may be involved in the formation and development of the heart.

Storage Rot of Dragon Fruit Caused by Gilbertella persicaria

In October 2011, a new disease of dragon fruit (Hylocereus costaricensis) was discovered in a fruit market in Yuanjiang, Yunnan Province, China. Small, light brown, water-soaked spots appeared initially and then coalesced, extending to the entire fruit in 6 days. Hyaline hyphae and light brown sporangia were observed over the entire surface of the infected fruit. On potato sucrose agar (PSA) the fungus produced a white, appressed colony that covered a 9-cm diameter petri dish in less than 5 days at 25°C. The sporangiophores were hyaline, light brown to grayish, 44.71 to 143.14 (average = 85.10) μm long, and arose directly from the non-septate substrate hyphae. The sporangia were spherical, single, and terminal and yellow-brown to brown when young turning to dark brown or black at maturity. Both the sporangiophores and sporangia were covered with calcium oxalate crystals. When mounted in a drop of water, the sporangium immediately broke longitudinally into two halves, releasing the spores and exposing a large pyriform columella at the tip of the sporangiophore. The spores were mostly globose to ellipsoid, aseptate, and 5.15 (3.71 to 7.86) × 6.30 (4.08 to 9.19) μm (n = 300). Two to three slender, hyaline appendages were attached to the ends of the spores. The cardinal growth temperatures of the pathogen were 10, 30, and 40°C and it grew faster in the dark than under 12-h alternating light-dark cycles. The fungus was identified as Gilbertella persicaria (1). To confirm the identification, the internal transcribed spacer region of the nuclear rDNA of one isolate was amplified using the fungal primers ITS1 and ITS4. The nucleotide sequence (Accession No. JQ951601) showed 98% homology with G. persicaria in GenBank (HM999958). Pathogenicity tests were carried out on two species of dragon fruit, H. costaricensis and H. undatus, by placing a 6-mm diameter young mycelial PSA agar disc on the surface of an asymptomatic fruit, either unwounded or wounded with a sterile needle. As the control, a plain PSA disc was used. Each inoculated fruit was placed in a moist chamber and incubated at 25°C. Three fruits were used per treatment and the experiment was repeated twice. The fruits rotted in 2 to 3 days, and the disease was especially serious on wounded fruits and on H. costaricensis. The fungus was reisolated from infected fruits. The controls did not show any disease symptoms. Inoculation studies were also made on other fruits but rot was produced only on peach, pear, and wounded tomato. To our knowledge, this is the first record of dragon fruit rot caused by G. persicaria. The fungus had been reported in China but caused no diseases (2). In India, it caused fruit rot of pear, tomato, and peach (3). To minimize the disease, dragon fruit should be stored at low temperature and in uncovered containers. References: (1) G. L. Benny. Mycologia 83:150, 1991. (2) J. Y. Cheng and H. Y. Mei. Acta Phytotax. Sin. 10:105, 1965. (3) M. D. Mehrotra. Mycopath. Mycol. Appl. 29:151, 1966.

First Report of Ralstonia solanacearum Causing Bacterial Wilt of Yacon in China

Yacon (Smallanthus sonchifolius) is an important cash crop in Yunnan Province, China. In 2003, yacon was introduced to Yunnan province as a novelty root crop and as an experimental source of natural sugars; now more than 15 provinces cultivate the crop. Yunnan is one of the major yacon producing areas of China, with up to 10,000 ha yielding up to 50,000 t of yacon, which is nearly half of the production in China. In April and May 2010, bacterial wilt of yacon was observed in the fields of Lion Mountain of Wuding County, Yunnan Province, China. In 2011, the disease occurred in approximately 1 ha of yacon, resulting in 10% crop loss in that area. The initial symptoms observed were irregular, black, necrotic lesions on leaf margins. After 4 to 7 days, leaves became totally necrotic, plants wilted, and black stripes were observed on plant stems. Within 2 to 3 weeks, more than 70% of leaves within the crop were wilted. Subsequently, the plants died and stems became brittle. When dead plants were pulled from the soil, tubers were found to have turned black. When diseased stems and/or petioles were cut with a sterile sharp knife or razor blade, bacterial ooze appeared on the cut ends. High populations of morphologically uniform bacteria were isolated from the diseased plants by conventional methods. When cultured on TZC (2,3,5-Triphenylte tetrazolium chloride) agar medium (3), colonies were large, elevated, fluidal, and entirely white with a pale red center. The isolated bacterium was gram-negative, grew aerobically, and did not form endospores. The cells were 0.5 to 0.7 × 1.5 to 2.0 μm and nonencapsulated. Ralstonia solanacearum was identified and confirmed as the pathogen on the basis of morphological and physiological characteristics, pathogenicity test, and 16S rDNA sequence analysis (1,4). The nucleotide sequence is available in GenBank (Accession No. HQ176322.1). The pathogenic strain belonged to race 1 and biovar 3 according to the pathogenicity and carbohydrate utilization tests (2). Koch's postulates were tested in the greenhouse, with 10 plants inoculated per species. Plants were inoculated with 15 μl of cell suspension containing 10⁶ to 10⁷ CFU ml^-1 deposited into the third axilla with a capillary tube. The bacteria could infect tomato, pepper, tobacco, potato, common sage (Salvia dugesii Fernald), and patchouli, and caused typical symptoms of wilt and black lesions, but could not infect leaves of swamp mahogany (Eucalyptus robusta Smith), stramonium (Dature stramonium Datura L.), ginger, or maize. To our knowledge, this is the first report of yacon as a host of R. solanacearum. Since the pathogen has a wide host range, monitoring of the vegetation in and around yacon fields should be implemented as a mandatory management measure to prevent disease spread. References: (1) C. A. Boucher et al. J. Bacteriol. 169:5626, 1987. (2) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (3) A. Kelman. Phytopathology 44:693, 1954. (4) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.

[Identification of metabolites of nobiletin in rats using ultra-performance liquid chromatography coupled with triple-quadrupole mass spectrometry]

In this study, metabolism of nobiletin in rats was studied using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). As a result, seven major metabolites were found in bile, urine and serum of rats. Three phase I products were assigned to be demethyl and di-demethyl products, and other four phase II products were assigned to be glucuronic and sulfonic conjugates. The four phase II metabolites were reported for the first time. Among the metabolites found in the present study, the glucuronic conjugates of demethyl-nobiletin played a predominant role in the metabolic pathway, indicating that its potential role for glucuronidation-related factors, such as gene polymorphism, drug-drug interaction, etc., in changing the active and toxic effect of nobiletin and that it should be paid more attention in further development.

Glucuronidation, a new metabolic pathway for pyrrolizidine alkaloids

Pyrrolizidine alkaloids (PAs) possess significant hepatotoxicity to humans and animals after metabolic activation by liver P450 enzymes. Metabolism pathways of PAs have been studied for several decades, including metabolic activation, hydroxylation, N-oxidation, and hydrolysis. However, the glucuronidation of intact PAs has not been investigated, although glucuronidation plays an important role in the elimination and detoxication of xenobiotics. In this study, PAs glucuronidation was investigated, and three important points were found. First, we demonstrated that senecionine (SEN)-a representative hepatotoxic PA-could be conjugated by glucuronic acid via an N-glucuronidation reaction catalyzed by uridine diphosphate glucuronosyl transferase in human liver microsomes. Second, glucuronidation of SEN was catalyzed not only by human but also other animal species and showed significant species differences. Rabbits, cattle, sheep, pigs, and humans showed the significantly higher glucuronidation activity than mice, rats, dogs, and guinea pigs on SEN. Kinetics of SEN glucuronidation in humans, pigs, and rabbits followed the one-site binding model of the Michaelis-Menten equation, while cattle and sheep followed the two-sites binding model of the Michaelis-Menten equation. Third, besides SEN, other hepatotoxic PAs including monocrotaline, adonifoline, and isoline also underwent N-glucuronidation in humans and several animal species such as rabbits, cattle, sheep, and pigs.

Stereochemical differentiation of C-7 hydroxyltaxane isomers by electrospray ionization mass spectrometry

In this study, different electrospray ionization mass spectrometric (ESI-MS) methods were utilized to analyze several pairs of taxane stereoisomers including paclitaxel and 7-epi-paclitaxel. Both ESI-MS and tandem mass spectrometry (MS/MS) techniques provided stereochemically dependent mass spectra in negative-ion mode, and all studied stereoisomers could be easily distinguished based on their characteristic ions or distinct fragmentation patterns. MS/MS experiments for several taxane analogues at various collision energies were performed to elucidate potential dissociation pathways. The gas-phase deprotonation potentials were also calculated to estimate the most thermodynamically favorable deprotonation site using DFT B3LYP/6-31G(d). The results of the theoretical studies agreed well with the fragmentation patterns of paclitaxel and 7-epi-paclitaxel observed from MS/MS experiments. In addition, it was found that liquid chromatography (LC)/ESI-MS was a useful and sensitive technique for assignment of C-7 taxane stereoisomers from realistic samples.

Histone deacetylase inhibitor trichostatin A modulates cell cycles in A2780 human ovarian cancer cell lines

PURPOSE OF INVESTIGATION

To analyze the effect and mechanism of TSA on cell cycles in human ovarian cancer cells.

METHODS

cells were cultured in RPMI 1640 supplemented. Flow cytometry analysis and RT-PCR were used to examine the distribution of cell cycles and the level of P21(WAF/CIPI) mRNA.

RESULTS

TSA induced increase of the G2/M phase accompanied by decrease of the S phase and enhanced level of P21(WAF/CIPI) mRNA in a concentration and time-dependent manner in A2780 cells.

CONCLUSION

Trichostatin A affects the activity of cyclin-dependent kinase through increased expression of P21(WAF/CIPI) mRNA. TSA causes A2780 cell blockage in the G2/M phase and inhibits cell proliferation of A2780 cells. The minimum level of active TSA is 100 nM and the minimum time is 12 hours. The effect relies on time and concentration.

Profiling of yew hair roots from various species using ultra-performance liquid chromatography/electrospray ionization mass spectrometry

An efficient and sensitive profiling approach to complex yew samples was developed using ultra-performance liquid chromatography/electrospray ionization mass spectrometry (UPLC/ESI-MS). The UPLC-based method displayed short analytical time and improved peak capability, as well as high sensitivity. The appropriate in-source collision-induced dissociation (CID) energy was employed to produce informative characteristic ions which could be used for stereochemical and sub-structural assignment of yew constituents. The method was successfully applied in the rapid screening of yew hair roots from various species, and 53 constituents including 47 taxoids were detected from partially purified root extract. Notably, C-7 hydroxytaxane stereoisomers could be identified based on their different fragment ions under the optimal profiling conditions. It was also observed that hair roots from different Taxus species exhibited nearly identical chemical distribution, indicating they had similar metabolic frameworks. Additionally, Taxus root resources also display benign medicinal perspective because they have relatively simple chemical profiles and possess high yields of valuable taxanes such as paclitaxel, cephalomannine, 10-deacetylpaclitaxel and 7-xylosyltaxanes.