Characterization of Hepatitis G Virus (GB-C Virus) Particles: Evidence for a Nucleocapsid and Expression of Sequences Upstream of the E1 Protein

Hepatitis G virus (HGV or GB-C virus) is a newly described virus that is closely related to hepatitis C virus (HCV). Based on sequence analysis and by evaluation of translational initiation codon preferences utilized during in vitro translation, HGV appears to have a truncated or absent core protein at the amino terminus of the HGV polyprotein. Consequently, the biophysical properties of HGV may be very different from those of HCV. To characterize HGV particle types, we evaluated plasma from chronically infected individuals with and without concomitant HCV infection by using sucrose gradient centrifugation, isopycnic banding in cesium chloride, and saline density flotation centrifugation. Similar to HCV, HGV particles included an extremely-low-density virion particle (1.07 to 1.09 g/ml) and a nucleocapsid of ~1.18 g/ml. One major difference between the particle types was that HGV was consistently more stable in cesium chloride than HCV. Plasma samples from chronically HGV-infected individuals and controls were assessed by a synthetic peptide-based immunoassay to determine if they contained HGV antibody specific for a conserved region in the coding region upstream of the E1 protein. Chronically HGV-infected individuals contained antibody to the HGV core protein peptide, whereas no binding to a hepatitis A virus peptide control was observed. Competitive inhibition of binding to the HGV peptide confirmed the specificity of the assay. These data indicate that HGV has a nucleocapsid and that at least part of the putative core region of HGV is expressed in vivo.     

铁还原细菌Shewanella oneidensis MR-4诱导水合氧化铁形成蓝铁矿的过程

【目的】研究铁还原细菌Shewanella oneidensis MR-4在细胞外诱导形成含铁矿物的矿物相、化学成分和形貌结构等特性及其变化,深化对铁还原细菌细胞外诱导矿化过程的认识。【方法】在以30 mmol/L乳酸钠为电子供体,10 mmol/L水合氧化铁为电子受体,[HCO_3~–]为30 mmol/L,[PO_4~(3–)]为5 mmol/L条件下,30°C恒温下厌氧培养,进行细菌生长和细胞外诱导矿化实验,定期采样测量反应体系的pH、生物量、Fe(Ⅱ)浓度;采用激光拉曼光谱(Raman)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X-射线衍射(XRD)等方法对不同时间点的矿化产物进行分析。【结果】MR-4在还原Fe(Ⅲ)的过程中,细胞快速生长,表明MR-4的Fe(Ⅲ)还原和乳酸氧化过程相互耦合,从而进行细胞生长,并在细胞外诱导矿物形成。对不同阶段矿化产物的综合分析表明,反应进行到约8 d时,无定形-弱结晶的水合氧化铁部分地转化为纳米尺寸的磁铁矿晶体颗粒;约16 d时,反应体系中开始出现蓝铁矿晶体颗粒;约20 d后,几乎所有矿物转化为纤维状或者叶片状的蓝铁矿。【结论】铁还原细菌Shewanella oneidensis MR-4细胞外诱导矿化过程受环境条件控制,当以乳酸钠和水合氧化铁分别作为电子供体和受体,相对高的[PO_4~(3–]/[HCO_3~–](1:6)时,水合氧化铁先转化为磁铁矿,最后大量转化为蓝铁矿。本研究为全面认识铁还原细菌的生物诱导矿化过程和评估其参与铁元素地球化学循环提供了新的数据。     

Inhibition of keratinocyte ferroptosis suppresses psoriatic inflammation

Psoriasis is a common, chronic, and recurrent inflammatory disease. It is characterized by hyperproliferation and abnormal differentiation of keratinocytes. Keratinocyte death is also involved in many pathophysiological conditions and amplifies the inflammatory cascade. As a newly recognized form of cell death, ferroptosis is involved in several inflammatory diseases. In this study, we aimed to investigate a previously unrecognized role for ferroptosis in psoriasis. Ferroptosis is mediated by lipid peroxidation and iron overload. Compared with normal lesions, the mRNA expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), prostaglandin-endoperoxide synthase 2 (PTGS2), and transferrin receptor (TFRC) were highly expressed in psoriatic lesions, with decreased levels of glutathione peroxidase 4 (GPX4), ferritin light chain (FTL), and ferritin heavy chain 1 (FTH1). The protein levels of ACSL4 and GPX4 were consistent with their mRNA levels. A similar tendency of ferroptosis was also observed in erastin-treated human primary keratinocytes and the Imiquimod (IMQ)-induced model of psoriasis. To investigate the correlation between inflammation and peroxidation, we analyzed single-cell RNA-sequencing data and identified 15 cell types. There was a high correlation between the activity of the lipid oxidation and the Th22/Th17 response in keratinocytes at a single-cell level. Moreover, ferrostatin-1 (Fer-1), a potent inhibitor of lipid peroxidation, suppressed ferroptosis-related changes in erastin-treated keratinocytes and alleviated psoriasiform dermatitis of IMQ-induced models. Additionally, Fer-1 blocked inflammatory responses in vitro and in vivo, reducing the production of cytokines including TNF-α, IL-6, IL-1α, IL-1β, IL-17, IL-22, and IL-23. This study revealed an expression pattern of ferroptosis in which specific molecules enhance inflammatory reactions in psoriasis.Subject terms: Cell death, Diseases     

H9N2 virus-derived M1 protein promotes H5N6 virus release in mammalian cells: Mechanism of avian influenza virus inter-species infection in humans

H5N6 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4 not only exhibits unprecedented intercontinental spread in poultry, but can also cause serious infection in humans, posing a public health threat. Phylogenetic analyses show that 40% (8/20) of H5N6 viruses that infected humans carried H9N2 virus-derived internal genes. However, the precise contribution of H9N2 virus-derived internal genes to H5N6 virus infection in humans is unclear. Here, we report on the functional contribution of the H9N2 virus-derived matrix protein 1 (M1) to enhanced H5N6 virus replication capacity in mammalian cells. Unlike H5N1 virus-derived M1 protein, H9N2 virus-derived M1 protein showed high binding affinity for H5N6 hemagglutinin (HA) protein and increased viral progeny particle release in different mammalian cell lines. Human host factor, G protein subunit beta 1 (GNB1), exhibited strong binding to H9N2 virus-derived M1 protein to facilitate M1 transport to budding sites at the cell membrane. GNB1 knockdown inhibited the interaction between H9N2 virus-derived M1 and HA protein, and reduced influenza virus-like particles (VLPs) release. Our findings indicate that H9N2 virus-derived M1 protein promotes avian H5N6 influenza virus release from mammalian, in particular human cells, which could be a major viral factor for H5N6 virus cross-species infection.     

患子宫内膜炎母猪产道致病菌谱分析及卟啉单胞菌的分离鉴定

【背景】子宫内膜炎是规模化养殖场母猪常患的生殖道疾病之一,对养殖业造成的经济损失较大,细菌感染是常见的病因之一,但具体病原及致病机制尚未完全明确。【目的】探究产道菌群对母猪子宫内膜炎的影响。【方法】采用第三代细菌16S rRNA基因全长高通量测序技术进行对比,研究健康和患有子宫内膜炎母猪产道菌群差异,并依据菌群分析结果对子宫内膜炎母猪产道分泌物进行细菌分离。建立荧光定量PCR计数方法测定母猪产道样品中的卟啉单胞菌数。【结果】健康和患子宫内膜炎母猪产道菌群的丰富度和多样性差异显著;与健康组母猪相比,患子宫内膜炎母猪产道菌群变形菌门(Proteobacteria)、拟杆菌门相对丰度显著增加(P<0.05)。在属分类水平上,健康母猪产道的主要优势菌属为金黄杆菌属、芽孢杆菌属、毛螺菌属等,这些优势属在患子宫内膜炎母猪产道丰度降低,患子宫内膜炎母猪产道丰度最高的菌属为埃希氏菌属(Escherichia)、Rodentibacter和卟啉单胞菌属(Porphyromonas)。在种水平上,Porphyromonas somerae是患子宫内膜炎母猪产道的主要条件性致病菌。依据菌群分析结果,本研究从子宫内膜炎母猪产道分泌物中分离到一株卟啉单胞菌,经鉴定该菌16S rRNA基因与Porphyromonas somerae DSM 23386 strain JCM 13867(NR_113090.1)相似性达99.04%。荧光定量PCR计数方法测定,子宫内膜炎母猪产道卟啉单胞菌数量显著高于健康母猪(P<0.05),推测卟啉单胞菌与该批次母猪子宫内膜炎病因有关。【结论】本研究为子宫内膜炎母猪的病因和发病机制奠定基础,并为其治疗提供理论依据。     

SRNAome and degradome sequencing analysis reveals specific regulation of sRNA in response to chilling injury in tomato fruit

Plant genomes encode diverse small RNA classes that function in distinct gene‐silencing pathways. To elucidate the intricate regulation of microRNAs (miRNAs) and endogenous small‐interfering RNAs (siRNAs) in response to chilling injury in tomato fruit, the deep sequencing and bioinformatic methods were combined to decipher the small RNAs landscape in the control and chilling‐injured groups. Except for the known miRNAs and ta‐siRNAs, 85 novel miRNAs and 5 ta‐siRNAs members belonging to 3 TAS families (TAS5, TAS9 and TAS10) were identified, 34 putative phased small RNAs and 740 cis/trans‐natural antisense small‐interfering RNAs (nat‐siRNAs) were also found in our results which enriched the tomato small RNAs repository. A large number of genes targeted by those miRNAs and siRNAs were predicted to be involved in the chilling injury responsive process and five of them were verified via degradome sequencing. Based on the above results, a regulatory model that comprehensively reveals the relationships between the small RNAs and their targets was set up. This work provides a foundation for further study of the regulation of miRNAs and siRNAs in the plant in response to chilling injury.     

Integrative analysis of circRNAs acting as ceRNAs involved in ethylene pathway in tomato

Circular RNAs (circRNAs) are a large class of non‐coding endogenous RNAs that could act as competing endogenous RNAs (ceRNAs) to terminate the mRNA targets' suppression of miRNAs. To elucidate the intricate regulatory roles of circRNAs in the ethylene pathway in tomato fruit, deep sequencing and bioinformatics methods were performed. After strict screening, a total of 318 circRNAs were identified. Among these circRNAs, 282 were significantly differentially expressed among wild‐type and sense‐/antisense‐LeERF1 transgenic tomato fruits. Besides, 1254 target genes were identified and a large amount of them were found to be involved in ethylene pathway. In addition, a sophisticated regulatory model consisting of circRNAs, target genes and ethylene was set up. Importantly, 61 circRNAs were found to be potential ceRNAs to combine with miRNAs and some of the miRNAs had been revealed to participate in the ethylene signaling pathway. This research further raised the possibility that the ethylene pathway in tomato fruit may be under the regulation of various circRNAs and provided a new perspective of the roles of circRNAs.     

<Emphasis Type="Italic">Trichophyton rubrum</Emphasis> Infection Characterized by Majocchi’s Granuloma and Deeper Dermatophytosis: Case Report and Review of Published Literature

Infections caused by Trichophyton rubrum are very common in dermatological disease. It most often appears as superficial cutaneous mycosis, such as tinea manuum, tinea pedis, and tinea corporis. However, deep infection caused by T. rubrum was rarely reported. We describe a case of mixed type of deep infection caused by T. rubrum in a 45-year-old man with no significant immunodeficiency. This patient had a history of onychomycosis on the toenails without regular treatment for nearly 6 years. And, he had erythema, papule, and nodules on the submandibular area, neck, and chest for almost 1 year. After treated with intravenous infusion of cefotiam for 2 weeks, the lesion aggravated. The fungal direct microscopic examination of pyogenic fluid was positive, and the fungal cultures that produced reddish-brown and yellow pigment showed cottony, wooly, and white colony. After the DNA sequencing, it was identified as T. rubrum. We gave the patient oral terbinafine 250 mg per day and bifonazole cream for external use. Six months later, the patient’s skin lesion was disappeared, and healthy nail growth was seen in two-thirds of nail bed. The terbinafine is effective against deep infection caused by T. rubrum.     

Effects of FGF2 and TGFbeta1 on the differentiation of human dental pulp stem cells in vitro

Two crucial growth factors, FGF2 and TGFbeta1, were investigated in this study to determine their inductive effects on the odontoblastic differentiation of human dental pulp stem cells (DPSCs) in vitro. DPSCs were isolated by immunomagnetic bead selection using the STRO-1 antibody, and then co-cultured respectively with FGF2, TGFbeta1 and FGF2+TGFbeta1. The results showed that FGF2 can exert a significant effect on the cell proliferation, while TGFbeta1 or FGF2+TGFbeta1 can initiate an odontoblast-like differentiation of DPSCs. Moreover, FGF2 can synergistically upregulate the effects of TGFbeta1 on the odontoblastic differentiation of DPSCs, as indicated by the increased alkaline phosphatase activity, the polarized cell appearance and secretary ultrastructural features, the formation of mineralized nodules and the gene/protein expression of dentin sialoprotein and dentin matrix protein-1. Together, FGF2 acted primarily on the cell proliferation, while TGFbeta1 and FGF2+TGFbeta1 mainly stimulated the odontoblastic differentiation of DPSCs. This study provides interesting progress in the odontoblastic differentiation of DPSCs induced by FGF2 and TGFbeta1.