GlcNAc-1,6-anhydro-MurNAc Moiety Affords Unusual Glycosyl Acceptor that Terminates Peptidoglycan Elongation.

Peptidoglycan (PG), an essential exoskeletal polymer in bacteria, is a well-known antibiotic target. PG polymerization requires the action of bacterial transglycosylases (TGases), which couple the incoming glycosyl acceptor to the donor. Interfering with the TGase activity can interrupt the PG assembly. Existing TGase inhibitors like moenomycin and Lipid II analogues always occupy the TGase active sites; other strategies to interfere with proper PG elongation have not been widely exploited. Inspired by the natural 1,6-anhydro-MurNAc termini that mark the ends of PG strands in bacteria, we hypothesized that the incorporation of an anhydromuramyl-containing glycosyl acceptor by TGase into the growing PG may effectively inhibit PG elongation. To explore this possibility, we synthesized 4-O-(N-acetyl-ß-d-glucosaminyl)-1,6-anhydro-N-acetyl-ß-d-muramyl-l-Ala-γ-d-Glu-l-Lys-d-Ala-d-Ala, 1, within 15 steps, and demonstrated that this anhydromuropeptide and its analogue lacking the peptide, 1-deAA, were both utilized by bacterial TGase as noncanonical anhydro glycosyl acceptors in vitro. The incorporation of an anhydromuramyl moiety into PG strands by TGases afforded efficient termination of glycan chain extension. Moreover, the preliminary in vitro studies of 1-deAA against Staphylococcus aureus showed that 1-deAA served as a reasonable antimicrobial adjunct of vancomycin. These insights imply the potential application of such anhydromuropeptides as novel classes of PG-terminating inhibitors, pointing toward novel strategies in antibacterial agent development.

A Strain-Promoted Divergent Chemical Steroidation Unveils Potent Anti-Inflammatory Pseudo-Steroidal Glycosides.

The development of novel agents with immunoregulatory effects is a keen way to combat the growing threat of inflammatory storms to global health. To synthesize pseudo-steroidal glycosides tethered by ether bonds with promising immunomodulatory potential, we develop herein a highly effective deoxygenative functionalization of a novel steroidal donor (steroidation) facilitated by strain-release, leveraging cost-effective and readily available Sc(OTf)3 catalysis. This transformation produces a transient steroid-3-yl carbocation which readily reacts with O-, C-, N-, S-, and P-nucleophiles to generate structurally diverse steroid derivatives. DFT calculations were performed to shed light on the mechanistic details of the regioselectivity, underlying an acceptor-dependent steroidation mode. This approach can be readily extended to the etherification of sugar alcohols to enable the achievement of a diversity-oriented, pipeline-like synthesis of pseudo-steroidal glycosides in good to excellent yields with complete stereo- and regiospecific control for anti-inflammatory agent discovery. Immunological studies have demonstrated that a meticulously designed cholesteryl disaccharide can significantly suppress interleukin-6 secretion in macrophages, exhibiting up to 99% inhibition rates compared to the negative control. These findings affirm the potential of pseudo-steroidal glycosides as a prospective category of lead agents for the development of novel anti-inflammatory drugs.

Observation of Diverse Asymmetric Structures in High-Dimensional Einstein-Podolsky-Rosen Steering.

Einstein-Podolsky-Rosen (EPR) steering, a distinctive quantum correlation, reveals a unique and inherent asymmetry. This research delves into the multifaceted asymmetry of EPR steering within high-dimensional quantum systems, exploring both theoretical frameworks and experimental validations. We introduce the concept of genuine high-dimensional one-way steering, wherein a high Schmidt number of bipartite quantum states is demonstrable in one steering direction but not reciprocally. Additionally, we explore two criteria to certify the lower and upper bounds of the Schmidt number within a one-sided device-independent context. These criteria serve as tools for identifying potential asymmetric dimensionality of EPR steering in both directions. By preparing two-qutrit mixed states with high fidelity, we experimentally observe asymmetric structures of EPR steering in the C^{3}⊗C^{3} Hilbert space. Our Letter offers new perspectives to understand the asymmetric EPR steering beyond qubits and has potential applications in asymmetric high-dimensional quantum information tasks.

URP20 improves corneal injury caused by alkali burns combined with pathogenic bacterial infection in rats.

Corneal alkali burns often occur in industrial production and daily life, combined with infection, and may cause severe eye disease. Oxidative stress and neovascularization (NV) are important factors leading to a poor prognosis. URP20 is an antimicrobial peptide that has been proven to treat bacterial keratitis in rats through antibacterial and anti-NV effects. Therefore, in this study, the protective effect and influence mechanism of URP20 were explored in a rat model of alkali burn together with pathogenic bacteria (Staphylococcus aureus and Escherichia coli) infection. In addition, human umbilical vein endothelial cells (HUVECs) and human corneal epithelial cells (HCECs) were selected to verify the effects of URP20 on vascularization and oxidative stress. The results showed that URP20 treatment could protect corneal tissue, reduce corneal turbidity, and reduce the NV pathological score. Furthermore, URP20 significantly inhibited the expression of the vascularization marker proteins VEGFR2 and CD31. URP20 also reduced the migration ability of HUVECs. In terms of oxidative stress, URP20 significantly upregulated SOD and GSH contents in corneal tissue and HCECs (treated with 200 µM H2O2) and promoted the expression of the antioxidant protein Nrf2/HO-1. At the same time, MDA and ROS levels were also inhibited. In conclusion, URP20 could improve corneal injury combined with bacterial infection in rats caused by alkali burns through antibacterial, anti-NV, and antioxidant activities.

CIP2A deficiency promotes depression-like behaviors in mice through inhibition of dendritic arborization.

Major depressive disorder (MDD) is a severe mental illness. Decreased brain plasticity and dendritic fields have been consistently found in MDD patients and animal models; however, the underlying molecular mechanisms remain to be clarified. Here, we demonstrate that the deletion of cancerous inhibitor of PP2A (CIP2A), an endogenous inhibitor of protein phosphatase 2A (PP2A), leads to depression-like behaviors in mice. Hippocampal RNA sequencing analysis of CIP2A knockout mice shows alterations in the PI3K-AKT pathway and central nervous system development. In primary neurons, CIP2A stimulates AKT activity and promotes dendritic development. Further analysis reveals that the effect of CIP2A in promoting dendritic development is dependent on PP2A-AKT signaling. In vivo, CIP2A deficiency-induced depression-like behaviors and impaired dendritic arborization are rescued by AKT activation. Decreased CIP2A expression and impaired dendrite branching are observed in a mouse model of chronic unpredictable mild stress (CUMS). Indicative of clinical relevance to humans, CIP2A expression is found decreased in transcriptomes from MDD patients. In conclusion, we discover a novel mechanism that CIP2A deficiency promotes depression through the regulation of PP2A-AKT signaling and dendritic arborization.

A case study of Duchenne muscular dystrophy caused by Alu element insertion in DMD gene and analysis of its gray-hair symptoms.

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive genetic disorder caused by mutations in the DMD gene, which leads to a deficiency of the dystrophin protein. The main mutation types of this gene include exon deletions and duplications, point mutations, and insertions. These mutations disrupt the normal expression of dystrophin, ultimately leading to the disease. In this study, we reported a case of DMD caused by an insertion mutation in exon 59 (E59) of the DMD gene. The affected child exhibited significant abnormalities in related biochemical markers, early symptoms of DMD, and multiple gray hair. His mother and sister were carriers with slightly abnormal biochemical markers. The mother had mild clinical symptoms, while the sister had no clinical symptoms. Other family members were genetically and physically normal. Sequencing and sequence alignment revealed that the inserted fragment was an Alu element from the AluYa5 subfamily. This insertion produced two stop codons and a polyadenylate (polyA) tail. To understand the impact of this insertion on the DMD gene and its association with clinical symptoms, exonic splicing enhancer (ESE) prediction indicated that the insertion did not affect the splicing of E59. Therefore, we speculated that the insertion sequence would be present in the mRNA sequence of the DMD gene. The two stop codons and polyA tail likely terminate translation, preventing the production of functional dystrophin protein, which may be the mechanism leading to DMD. In addition to typical DMD symptoms, the child also exhibited premature graying of hair. This study reports, for the first time, a case of DMD caused by the insertion of an Alu element into the coding region of the DMD gene. This finding provides clues for studying gene mutations induced by Alu sequence insertion and expands the understanding of DMD gene mutations.

[Mechanism of ultrafiltration extract of Angelicae Sinensis Radix and Hedysari Radix regulates HIF-1α signaling pathway mediated by renal hypoxia to ameliorate renal fibrosis in DKD rats].

This study explored the mechanism of the ultrafiltration extract of Angelicae Sinensis Radix and Hedysari Radix in ameliorating renal fibrosis in the rat model of diabetic kidney disease(DKD) based on the expression of hypoxia-inducible factor-1α(HIF-1α)/vascular endothelial growth factor(VEGF) and HIF-1α/platelet-derived growth factor(PDGF)/platelet-derived growth factor receptor(PDGFR) signaling pathways in the DKD rats. After 1 week of adaptive feeding, 50 male SPF-grade Wistar rats were randomized into a blank group(n=7) and a modeling group. After 24 h of fasting, the rats in the modeling group were subjected to intraperitoneal injection of streptozocin and fed with a high-sugar and high-fat diet to establish a DKD model. After modeling, the rats were randomly assigned into model(n=7), low-dose ultrafiltration extract(n=7), medium-dose ultrafiltration extract(n=7), irbesartan(n=8), and high-dose ultrafiltration extract(n=8) groups. After intervention by corresponding drugs for 12 weeks, the general conditions of the rats were observed. The body weights and blood glucose levels of the rats were measured weekly, and the 24 h urinary protein(24hUP) was measured at the 6th and 12th weeks of drug administration. After the last drug administration, the renal function indicators were determined. Masson staining was employed to observe the pathological changes of the renal tissue. The expression of prolyl hydroxylase domain 2(PHD2) and HIF-1α in the renal tissue was detected by immunohistochemistry(IHC). Real-time qPCR was employed to determine the mRNA levels of PHD2, VEGF, PDGF, and PDGFR in the renal tissue. Western blot was employed to determine the protein levels of HIF-1α, VEGF, PDGF, and PDGFR in the renal tissue. The results showed that compared with the model group, drug administration lowered the levels of glycosylated serum protein(GSP), aerum creatinine(Scr), and blood urea nitrogen(BUN) in a dose-dependent manner(P<0.05 or P<0.01) and mitigated the pathological changes in the renal tissue. Furthermore, drug administration up-regulated mRNA level of PHD2(P<0.05 or P<0.01), down-regulated the mRNA levels of VEGF, PDGF, and PDGFR(P<0.05 or P<0.01) and the protein levels of HIF-1α, VEGF, PDGF, and PDGFR(P<0.01) in the renal tissue, and increased the rate of PHD2-positive cells(P<0.01). In conclusion, the ultrafiltration extract of Angelicae Sinensis Radix and Hedysari Radix effectively alleviated the renal fibrosis in DKD rats by inhibiting the expression of key proteins in the HIF-1α signaling pathway mediated by renal hypoxia and reducing extracellular matrix(ECM) deposition.

Clinical effectiveness of Er,Cr:YSGG lasers in non-surgical treatment of chronic periodontitis: a meta-analysis of randomized controlled trials.

The meta-analysis aimed to systematically evaluate all the available pieces of evidence concerning the clinical effectiveness of Er,Cr:YSGG lasers (erbium, chromium, yttrium scandium gallium garnet laser) in the non-surgical treatment of patients with chronic periodontitis, and provide guidance for clinicians about the application of Er,Cr:YSGG lasers during the process of non-surgical periodontal treatments. The meta-analysis was conducted with data extracted from 16 randomized controlled clinical trials (RCTs) that compare Er,Cr:YSGG lasers adjunct/substitute to scaling and root planing (SRP) with SRP alone for the treatment of chronic periodontitis published in English or Chinese from January 2000 to January 2020. The weighted mean differences (WMDs) and 95% confidence intervals (CIs) were counted for probing depth (PD) reduction, clinical attachment level (CAL) gain, and visual analogue scale (VAS) score. Heterogeneity of each study was evaluated with the Q test. The publication bias was measured using Begg's adjusted rank correlation test. Sixteen RCTs with 606 patients were included in the meta-analysis. There were statistically significant differences between Er,Cr:YSGG lasers adjunct/substitute to SRP and SRP alone in the PD reduction at 1-month follow-up (WMD = ­ 0.35, 95% CI [- 0.63, ­ 0.07], P = 0.013), 3-month follow-up (WMD = - 0.342, 95% CI [- 0.552, - 0.132], P = 0.001), CAL gain at 3-month follow-up (WMD = - 0.17, 95% CI [- 0.31, 0.03], P = 0.017), and VAS score (WMD = - 2.395, 95% CI [- 3.327, - 1.464], P = 0.000) immediately after treatment. There were no significant differences of PD reduction and CAL change at 6-month follow-up. The present meta-analysis indicated that Er,Cr:YSGG lasers provided additional effectiveness in PD reduction and CAL gain at short-term follow-ups and there was less pain compared with SRP alone.

Uncarboxylated osteocalcin ameliorates hepatic glucose and lipid metabolism in KKAy mice via activating insulin signaling pathway.

Osteocalcin, expressed in osteoblasts of the bone marrow, undergoes post-translational carboxylation and deposits in mineralized bone matrix. A portion of osteocalcin remains uncarboxylated (uncarboxylated osteocalcin, GluOC) that is released into blood where it functions as a hormone to regulate insulin secretion and insulin sensitivity. As insulin resistance is closely associated with metabolic syndrome, this study is aimed to elucidate how GluOC regulates glucose and lipid metabolism in KKAy mice, an animal model displaying obese, hyperglycemia, hyperinsulinemia, insulin resistance, and hepatic steatosis. GluOC (3, 30 ng/g per day, ig) was orally administered to female KKAy mice for 4 weeks. Whole-body insulin sensitivity, glucose metabolism, hepatic steatosis, dyslipidemia were examined using routine laboratory assays. We found that GluOC administration significantly enhanced insulin sensitivity in KKAy mice by activating hepatic IRß/PI3K/Akt pathway and elevated the whole-body insulin sensitivity with decreased FPI and HOMA-IR index. Furthermore, GluOC administration alleviated hyperglycemia through suppressing gluconeogenesis and promoting glycogen synthesis in KKAy mice and in cultured hepatocytes in vitro. Moreover, GluOC administration dose-dependently ameliorated dyslipidemia and attenuated hepatic steatosis in KKAy mice by inhibiting hepatic de novo lipogenesis and promoting fatty-acid ß-oxidation. These results demonstrate that GluOC effectively enhances hepatic insulin sensitivity, improves hyperglycemia and ameliorates hepatic steatosis in KKAy mice, suggesting that GluOC could be a promising drug candidate for treating metabolic syndrome.

siRNA-mediated NCAM1 gene silencing suppresses oxidative stress in pre-eclampsia by inhibiting the p38MAPK signaling pathway.

Pre-eclampsia (PE), whose pathophysiology and etiology remain undefined, represents a leading consequence of fetal and maternal mortality and morbidity. Oxidative stress (OS) is recognized to involve in this disorder. In this study, we hypothesized that neural cell adhesion molecule 1 (NCAM1) gene silencing would suppress the OS in the pregnancy complicated by PE. Initially, clinical samples were collected for determination of NCAM1 expression in placental tissues and levels of OS products in blood. To assess the regulatory mechanism of NCAM1 knockdown on OS, we used small interfering RNA (siRNA) to silence NCAM1 expression in human umbilical vein endothelial cells (HUVECs). Next, cells were treated with or without hypoxia/reoxygenation to observe the level changes of OS products and p38 mitogen-activated protein kinase (p38MAPK) pathway-related genes. Finally, an evaluation of HUVEC migration and invasion abilities was conducted by wound-healing and transwell assays. Placenta of pregnancy with PE presented significantly increased NCAM1 expression in comparison to placenta of normal pregnancy. Meanwhile, enhanced OS in blood of pregnant women with PE was observed relative to women with normal pregnancy. siRNA-mediated knockdown of NCAM1 gene could inhibit the p38MAPK signaling pathway, repress OS, and promote cell migration and invasion in HUVECs, indicating that NCAM1 inhibition could reduce the influence of PE. Importantly, blocking the p38MAPK signaling pathway reversed the inhibitory role of NCAM1 gene silencing on PE. Collectively, this study defines potential role of NCAM1 gene silencing as a therapeutic target in PE through inhibiting OS and enhancing HUVEC migration and invasion by disrupting the p38MAPK signaling pathway.

Switching Lamivudine with Adefovir Dipivoxil Combination Therapy to Entecavir Monotherapy Provides Better Viral Suppression and Kidney Safety.

Introduction: Most chronic hepatitis B (CHB) patients in China are primitively treated with a combination of lamivudine (LAM) and adefovir dipivoxil (ADV). Although antiviral resistance can be avoided with this combination therapy, using it can have harmful side effects related to ADV, specifically kidney and bone injury. This study was designed to compare viral suppression and kidney safety when switching LAM and ADV combination therapy de novo to entecavir (ETV) monotherapy in patients with CHB and compensated hepatic cirrhosis. Materials and methods: In total, 360 CHB and compensated liver cirrhosis patients who received treatment of LAM and ADV combination therapy for more than 1 year were included in this study. One hundred and eighty patients continued combination therapy to serve as a control group and the other 180 patients were switched to ETV monotherapy to serve as the experimental group. The total course of therapy was 3 years. Laboratory studies were done every 3 months to measure liver and kidney function. Studies included glomerular filtration rate (eGFR), HBV-DNA, urine ß2-microglobulin (ß2-M) and retinol binding protein (RBP). Results: In the experimental group, an HBV-DNA level below 20 IU/ml was found in 77.65%, 85.88%, and 94.77% in years 1, 2, and 3, respectively. In the control group, HBV-DNA levels were below 20 IU/ml in 69.66%, 75.42%, and 85.80% in years 1, 2, and 3, respectively. Low HBV-DNA levels in the experimental group were significantly less common than in the control group on the second and third year; P values were 0.009 and 0.006 for years 2 and 3, respectively. The cumulative genetic mutation rate was 3.49% in the experimental group and 8.88% in the control group (P=0.044). Decreases in eGFR more than 30% from baseline were found in 0%, 0.56%, and 1.74% of patients in the experimental group and 4.49%, 9.14% and 14.79% in patients in the control group in the first, second, and third year, respectively. Serum creatinine more than 50 µmol/L above baseline was found in 0%, 0% and 1.74% of patients in the experimental group and 1.12%, 4.00% and 5.32% of patients in the control group in years 1, 2, and 3, respectively. The urine ß2-M and RBP levels were abnormal more often in the experimental group than in the control group. Conclusion: Switching to ETV monotherapy can decrease HBV-DNA levels, reduce the genetic mutation rate, and prevent renal damage caused by LAM and ADV combination therapy in patients with CHB and compensated liver cirrhosis. Patients receiving LAM and ADV combination therapy de novo should be switched to ETV monotherapy immediately.

Methyl Helicterate Inhibits Hepatic Stellate Cell Activation Through Modulation of Apoptosis and Autophagy.

BACKGROUND/AIMS: Activated hepatic stellate cells (HSCs) are the major source of extracellular matrix (ECM). Therefore inhibiting HSC activation is considered as an effective strategy to inhibit the process of liver fibrosis. This study aimed to investigate the underlying mechanism of methyl helicterate (MH) isolated from Helicteres angustifolia on the activation of HSCs. METHODS: HSC-T6 cells were treated with various concentration of MH and autophagy was inhibited by 3-Methyl adenine (3-MA) or RNA interference. Cell viability was observed by MTT assay and cell colony assay. Cell cycle and apoptosis were analyzed using flow cytometry. Autophagic vacuoles were observed by transmission electron microscopy and monodansyl cadaverine (MDC) staining. Moreover, autophagy-related genes and proteins were detected using real-time PCR and Western blot assays, respectively. RESULTS: MH significantly inhibited HSC activation, as evidenced by the inhibition of cell viability, colony formation and the expression of α-SMA and collagen I. MH caused cell cycle arrest in G2/M phase. Moreover, MH significantly induced apoptosis through regulating the mitochondria-dependent pathway and the activity of caspases. MH treatment significantly increased lysosomes and autophagosomes, and enhanced the formation of autophagic vacuoles and autophagic flux. Interestingly, inhibiting autophagy by 3-MA or RNA interference abolished the ability of MH in inhibiting HSC activation. On the other hand, induction of autophagy promoted MH-induced HSC apoptosis. Further study showed that MH-induced HSC apoptosis and autophagy was mediated by the JNK and PI3K/Akt/mTOR pathways. CONCLUSION: Our results demonstrate that MH-induced HSC apoptosis and autophagy may be one of the important mechanisms for its anti-fibrosis effect.

Semirigid Tripodal Ligand Based Uranyl Coordination Polymer Isomers Featuring 2D Honeycomb Nets.

We report five novel uranyl coordination polymers, [(CH3)2NH2]UO2(BTPCA) (1), [(CH3)2NH2]UO2(BTPCA) (2), [(CH3)2NH2]2[UO2(BTPCA)][UO2(BTPCA)]·(H2O)5.5 (3), [(CH3)2NH2]2(UO2)2(BTPCA)2·(H2O)3 (4), and [(CH3)2NH2]UO2(BTPCA) (5), by the utilization of semirigid ligand 1,1',1″-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid (H3BTPCA) and uranyl nitrate through solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that the five compounds share a similar structure composition and local coordination mode to the exclusion of disordered water or DMF molecules. Each UO2(COO)3- motif is connected to six neighboring units through three BTPCA3- ligands, generating an infinite uranyl honeycomb (6, 3) net. The structures of all the five compounds consist of 2D honeycomb nets of various degrees of distortions, which are induced by the flexibility of piperidine rings. The dimethylamine cations and solvent molecules fill in the space between layers. Therefore, these five compounds are isomers in a broad sense. Notably, both compounds 3 and 4 possess 2-fold interpenetrated structures. For compound 5, the distance between the neighboring 2D honeycomb nets is 7.253 Å. This is the largest distance between the 2D honeycomb nets in uranyl-based coordination polymers, to the best of our knowledge. In addition, compounds 1, 2, and 4 are also characterized by infrared spectroscopy (IR), thermogravimetric analysis (TG), powder X-ray diffraction (PXRD), and luminescence properties.

Novel Viologen Derivative Based Uranyl Coordination Polymers Featuring Photochromic Behaviors.

A series of novel uranyl coordination polymers have been synthesized by hydrothermal reactions. Both complexes 1 and 2 prosess two ipbp- ligands (H2 ipbpCl=1-(3,5-dicarboxyphenyl)-4,4'-bipyridinium chloride), one uranyl cation, and two coordination water molecules, which can further extend to 2D networks through hydrogen bonding. In complex 1, two sets of equivalent nets are entangled together, resulting in a 2D + 2D → 3D polycatenated framework. In complex 2, the neighbouring equivalent nets interpenetrate each other, forming a twofold interpenetrated network. Complexes 3 and 4 are isomers, and both of them are constructed from (UO2 )2 (OH)2 dinuclear units, which are connected with four ipbp- ligands. The 3D structures of complexes 3 and 4 are similar along the b axis. Similar to other viologen-based coordination polymers, complexes 3 and 4 exhibit photochromic and thermochromic properties, which are rarely observed in actinide coordination polymers. Unlike the monotonous coordination mode in complexes 1-4, the ipbp- ligands feature a µ3 -bridge through two kinds of coordination modes in complex 5. Notably, complex 5 presents a unique example in which terminal pyridine nitrogen atom is involved in the coordination.

Solvent-Dependent Synthesis of Porous Anionic Uranyl-Organic Frameworks Featuring a Highly Symmetrical (3,4)-Connected ctn or bor Topology for Selective Dye Adsorption.

Two highly symmetrical (3,4)-connected uranyl-organic frameworks (UOFs) were synthesized by a judicious combination of D3h -symmetrical triangular [UO2 (COO)3 ]- and Td symmetrical tetrahedral tetrakis(4-carboxyphenyl)methane (H4 MTB). These two as-synthesized UOFs possess similar structural units and coordination modes but totally different topological structures, namely ctn net and bor net. Solvent-induced interpenetration and a morphology change are observed. The two compounds exhibit crystal transformation via a dissolution-crystallization process. Adsorption experiments in CH3 OH solution indicate that both of them can selectively remove positively charged dyes over negatively charged and neutral dyes. Moreover, the electronic structural and bonding properties of the two compounds were systematically explored by density functional theory (DFT) calculations.

Effects of a NTG-based chemical mutagenesis on the propamocarb-tolerance of the nematophagous fungus Lecanicillium attenuatum.

Lecanicillium attenuatum is an important nematophagous fungus with potential as a biopesticide for control of plant-pathogenic nematodes. However, relatively low fungicide-tolerance limits its application in the field. To improve the propamocarb-tolerance of L. attenuatum, a NTG-based mutagenesis system was established. Among different combinations of NTG concentration and treatment time in the first-round NTG treatment, the treatment of 1.0mg/ml NTG for 60min gave a proper conidial lethality rate of 84.6% and the highest positive mutation rate of 7.7%, and then produced the highest propamocarb-tolerant mutant LA-C-R1-T4-M whose EC50 value reached to 1050.0µg/ml. The positive mutation range was 105.1% in the first-round NTG treatment. Multiple-round NTG treatment was further employed to enhance the propamocarb tolerance of L. attenuatum. The positive mutation range was significantly accumulated to 179.3% on the third-round NTG treatment, and then appeared to level-off and remained constant. These results indicated that multiple-round NTG treatment had a significant accumulative effect on fungal tolerance to propamocarb. Among all chemical-mutants, the LA-C-R3-M was the highest tolerant to propamocarb, whose EC50 value was increased 2.79-fold compared to the wild-type strain, and it was mitotic stable after 20 passages on PDA medium. Colony growth, conidia yield and conidial germination on plates, and parasitism of nematode eggs of M. incognita and H. glycines were not significantly changed by the NTG-based mutagenesis compared to the wild-type strain in either single- or multiple-round NTG treatment. In conclusion, we succeeded in improving the propamocarb tolerance of L. attenuatum via the optimized NTG-based mutagenesis system. The improved strain LA-C-R3-M could be potentially applied with propamocarb in the field.

Functions of microRNA in seed development, dormancy and germination processes.

In plants, microRNAs (miRNAs) are a class of non-coding small RNAs that play important roles in various biological processes, such as seed development, dormancy and germination. In these stages, seeds are regulated by various extrinsic environmental factors and intrinsic hormones. Different species of seeds have distinct development and dormancy characteristics. Recent investigations have identified more and more miRNAs to regulate seed morphogenesis, material metabolism and stress response capacities through hormonal signal transduction, antioxidant effects and transcription factors, etc. In this review, we summarize recent progresses on regulatory mechanisms of miRNAs, and also complex multilevel regulation of miRNAs in the process of seed development, dormancy and germination. We hope to provide insights into further research.

The overlap of upper functional gastrointestinal disorders with irritable bowel syndrome in Chinese outpatients: A multicenter study.

BACKGROUND AND AIM: Irritable bowel syndrome (IBS) is a common functional bowel disease, and the overlap with upper functional gastrointestinal disorders (FGIDs) is popular. However, the coexistent upper GI symptom profiles, upper FGID spectra, and related risk factors among IBS subjects remain unclear in mainland of China. METHODS: Consecutive patients from the outpatient gastroenterology clinics of three tertiary hospitals in China were enrolled in this multicenter study. All upper GI symptoms occurring at least once a week in the last 3 months were recorded. Diagnostic criteria of functional esophageal, gastroduodenal disorders and IBS were based on Rome III criteria. Risk factors were assessed using a multivariate logistic regression model. RESULTS: Of the 8906 consecutive patients, 751 patients met Rome III criteria for IBS and 735 IBS patients participated in the interview. Postprandial fullness (30.6%), belching (27.1%), and regurgitation (21.8%) were the three most prevalent upper GI symptoms in IBS. Functional dyspepsia (FD, 36.7%), belching disorders (27.1%), and functional heartburn (16.3%) were the three most frequent upper FGID in IBS patients. Female sex, divorced or widowed versus married status, defecation straining, reduced bowel movement, mixed IBS, abdominal distention, mild abdominal pain, moderate discomfort were positively associated with IBS-FD overlap. Female sex, drinking, moderate discomfort, and mild to moderate distension were independent risk factors for IBS-belching disorder overlap. CONCLUSIONS: The study provides detailed overlap spectra of upper FGID with IBS. Mixed IBS is an important risk factor for IBS-FD overlap, which deserved more concern.

Genetic improvement of the nematicidal fungus Lecanicillium attenuatum against Heterodera glycines by expression of the Beauveria bassiana Cdep1 protease gene.

Lecanicillium attenuatum is an important nematophagous fungus with potential as a biopesticide against plant-parasitic nematodes. The Pr1A-like cuticle-degrading protease (Cdep1) gene originating from the entomopathogenic fungus Beauveria bassiana was transformed into the nematophagous fungus L. attenuatum using a polyethylene-glycol mediated protoplast-based transformation system. Protease activity was increased 0.64- to 1.63-fold 2-10d after growth in the transformed L. attenuatum. Inhibition of egg-hatching and J2 motility of soybean cyst nematodes (Heterodera glycines) by cell-free fungal culture filtrates were enhanced by 17-76% 2-14d and 43-152% 1-13d after incubation, respectively.

[Investigating the effects of compound WS090152 on non-alcoholic fatty liver in mice].

To investigate the effects and the mechanism of compound WS090152 on non-alcoholic fatty liver (NAFL), the compound was administrated in C57BL/6J mice fed a high fat diet at 50 mg·kg(-1) by lavage. The lipid accumulation in liver was determined by the content of hepatic triglyceride (TG) and the histological pathological analysis. The levels of body weight gain, serum total cholesterol (TC) and TG were measured to evaluate lipid metabolism. Insulin sensitivity was determined by glucose infusion rate (GIR) value in hyperinsulinemic-euglycemic clamp test. The expression of related proteins in liver was measured by Western blot. The effect on the target protein tyrosine phosphatase 1B (PTP1B) was assessed by the activity of recombinate human PTP1B in vitro, and by the expressions of PTP1B in vivo, respectively. The content of hepatic TG (P<0.05) and the pathological changes of the livers (P<0.01) were attenuated, insulin resistance was improved, (P<0.01), and the levels of serum TC (P<0.01) and serum TG (P<0.05) were reduced by WS090152 treatment in the mice. The recombinant h PTP1B activity was significantly inhibited with IC50 value of 0.34 µmol·L(-1); the expression of PTP1B was significantly downregulated, and the phosphorylation of its downstream insulin receptor (IR), and AKT was upregulated by WS090152 administration in the livers of NAFL mice. The expression of hepatic lipogenesis-related proteins-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) was attenuated. These results suggest that compound WS090152 can ameliorate NAFL by increasing insulin sensitivity and decreasing hepatic lipogenesis probably through inhibition of PTP1B.