Association of low-level viremia with mortality among people living with HIV on antiretroviral therapy in Dehong, Southwest China: A retrospective cohort study.

OBJECTIVES: To investigate the association of low-level viremia (LLV) with mortality among people living with HIV (PLHIV) on antiretroviral therapy (ART) in Dehong, Southwest China. METHODS: We analysed data collected from a cohort of PLHIV on ART in Dehong. PLHIV were enrolled in this cohort after they started ART, with viral load (VL) tested once a year afterwards. Each VL level was then categorized into one of the four groups: <50, 50-199, 200-999 and ≥1000 copies/ml. VL levels of 50-199 and 200-999 copies/ml were defined as LLV. The VL level for each participant was re-categorized and fitted into an extended Cox regression model as a time-varying covariate to examine the associations of VL level with all-cause and AIDS-related deaths. RESULTS: Among the included 7273 of 8762 PLHIV in this study, median age (interquartile range, IQR) was 36 (30-43) years and 59.9% were male. The patients were followed up for a median duration (IQR) of 6.2 (4.3-8.2) years. Compared with VL <50 copies/ml, LLV 200-999 copies/ml (adjusted hazard ratio [aHR] and 95% confidence interval [95% CI]: 1.56 [1.04, 2.32]) were associated with elevated risk of all-cause mortality and LLV50-199 (aHR [95% CI]: 1.00 [0.68, 1.45]) were not. Similarly, only LLV200-999 copies/ml (aHR [95% CI]: 2.37 [1.36, 4.14]) corresponded to higher risk of AIDS-related mortality. CONCLUSIONS: This study suggests that PLHIV on ART may have elevated death risks even though the viremia is suppressed at a low level. Interventions targeting PLHIV with LLV should be developed to reduce their mortality.

A young patient with heart failure was diagnosed with extra-adrenal paraganglioma: a case report.

BACKGROUND: We present a case of pelvic paraganglioma that presented with heart failure as the primary symptom. CASE PRESENTATION: A 35-year-old man was admitted to hospital due to heart failure. Contrast-enhanced pelvic CT showed mass shadows in the posterior wall of the bladder and multiple enlarged lymph nodes in the retroperitoneal area. Ultrasound-guided puncture was performed, and the pathologic diagnosis was extra-adrenal paraganglioma. The patient refused any chemotherapy and died within six months of diagnosis. CONCLUSION: The possibility of neuroendocrine-related tumors, for example paragangliomas, should be considered in young patients with heart failure, especially those with concomitant hypertension and diabetes.

Genome-wide survey of Gγ subunit gene family in eight Rosaceae and expression analysis of PbrGGs in pear (Pyrus bretschneideri).

BACKGROUND: Heterotrimeric G-proteins, composed of Gα, Gß and Gγ subunits, are important signal transmitters, mediating the cellular response to multiple stimuli in animals and plants. The Gγ subunit is an essential component of the G-protein, providing appropriate functional specificity to the heterotrimer complex and has been well studied in many species. However, the evolutionary history, expression pattern and functional characteristics of Gγ subunits has not been explored in the Rosaceae, representing many important fruit crops. RESULTS: In this study, 35 Gγ subunit genes were identified from the eight species belonging to the Rosaceae family. Based on the structural gene characteristics, conserved protein motifs and phylogenetic analysis of the Gγ subunit genes, the genes were classified into three clades. Purifying selection was shown to play an important role in the evolution of Gγ subunit genes, while a recent whole-genome duplication event was the principal force determining the expansion of the Gγ subunit gene family in the subfamily Maloideae. Gγ subunit genes exhibited diverse spatiotemporal expression patterns in Chinese white pear, including fruit, root, ovary and bud, and under abiotic stress conditions, the relative expression of Gγ subunit genes were up-regulated or down-regulated. In addition, seven of the Gγ subunit proteins in pear were located on the plasma membrane, in the cytoplasm or nucleus. CONCLUSION: Overall, this study of the Gγ subunit gene family in eight Rosaceae species provided useful information to better understand the evolution and expression of these genes and facilitated further exploration of their functions in these important crop plants.

Genome-wide survey of sucrose non-fermenting 1-related protein kinase 2 in Rosaceae and expression analysis of PbrSnRK2 in response to ABA stress.

BACKGROUND: The members of the sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family are specific serine/threonine protein kinases in plants that play important roles in stress signal transduction and adaptation. Because of their positive regulatory roles in response to adverse conditions, the genes encoding thes proteins are considered potential candidates for breeding of plants for disease resistance and genetic improvement. However, there is far less information about this kinase family, and the function of these genes has not been explored in Rosaceae. RESULTS: A genome-wide survey and analysis of the genes encoding members of the SnRK2 family were performed in pear (Pyrus bretschneideri) and seven other Rosaceae species. A total of 71 SnRK2 genes were identified from the eight Rosaceae species and classified into three subgroups based on phylogenetic analysis and structural characteristics. Purifying selection played a crucial role in the evolution of SnRK2 genes, and whole-genome duplication and dispersed duplication were the primary forces underlying the characteristics of the SnRK2 gene family in Rosaceae. Transcriptome data and qRT-PCR assay results revealed that the distribution of PbrSnRK2s was very extensive, including across the roots, leaves, pollen, styles, and flowers, although most of them were mainly expressed in leaves. In addition, under stress conditions, the transcript levels of some of the genes were upregulated in leaves in response to ABA treatment. CONCLUSIONS: This study provides useful information and a theoretical introduction for the study of the evolution, expression, and functions of the SnRK2 gene family in plants.

Lumbar vertebral osteoradionecrosis: a rare case report with 10-year follow-up and brief literature review.

BACKGROUND: Osteoradionecrosis (ORN) is a complication that occurs after radiotherapy for head or neck malignancies. ORN of the spine is rare, with only few cases affecting the cervical spine reported to date. To our knowledge, no case of lumbar ORN has been reported. We report a rare case of ORN in the lumbar spine that occurred 2 years after radiotherapy and perform a literature review. CASE PRESENTATION: We present a case of lumbar ORN that occurred 2 years after radiotherapy for gallbladder carcinoma. The patient was successfully treated conservatively and followed up for > 10 years. CONCLUSIONS: ORN of the spine is a rare complication of radiotherapy. Spinal ORN is clinically described as a chronic disease with a slow onset. The most common presenting symptom of spinal ORN is pain. However, as ORN progresses, spinal kyphosis and instability can lead to neurological compression and thus to induced myelopathy or radiculopathy. Treatment of spinal ORN is comprehensive, including orthosis, medication, hyperbaric oxygen therapy, surgery, and new treatment combinations of pentoxifylline and tocopherol. The surgical rate for spinal ORN is relatively high.

Molecular Evolutionary and Expression Pattern Analysis of AKR Genes Shed New Light on GalUR Functional Characteristics in Brassica rapa.

The aldo-keto reductase (AKR) superfamily plays a major role in oxidation-reduction in plants. D-galacturonic acid reductase (GalUR), an ascorbic acid (AsA) biosynthetic enzyme, belongs to this superfamily. However, the phylogenetic relationship and evolutionary history of the AKR gene family in plants has not yet been clarified. In this study, a total of 1268 AKR genes identified in 36 plant species were used to determine this phylogenetic relationship. The retention, structural characteristics, and expression patterns of AKR homologous genes in Brassica rapa and Arabidopsis thaliana were analyzed to further explore their evolutionary history. We found that the AKRs originated in algae and could be divided into A and B groups according to the bootstrap value; GalURs belonged to group A. Group A AKR genes expanded significantly before the origin of angiosperms. Two groups of AKR genes demonstrated functional divergence due to environmental adaptability, while group A genes were more conservative than those in group B. All 12 candidate GalUR genes were cloned, and their expression patterns under stress were analyzed, in Pak-choi. These genes showed an obvious expression divergence under multiple stresses, and BrcAKR22 exhibited a positive correlation between its expression trend and AsA content. Our findings provide new insights into the evolution of the AKR superfamily and help build a foundation for further investigations of GalUR's functional characteristics.

Boosting the biosynthesis of betulinic acid and related triterpenoids in Yarrowia lipolytica via multimodular metabolic engineering.

BACKGROUND: Betulinic acid is a pentacyclic lupane-type triterpenoid and a potential antiviral and antitumor drug, but the amount of betulinic acid in plants is low and cannot meet the demand for this compound. Yarrowia lipolytica, as an oleaginous yeast, is a promising microbial cell factory for the production of highly hydrophobic compounds due to the ability of this organism to accumulate large amounts of lipids that can store hydrophobic products and supply sufficient precursors for terpene synthesis. However, engineering for the heterologous production of betulinic acid and related triterpenoids has not developed as systematically as that for the production of other terpenoids, thus the production of betulinic acid in microbes remains unsatisfactory. RESULTS: In this study, we applied a multimodular strategy to systematically improve the biosynthesis of betulinic acid and related triterpenoids in Y. lipolytica by engineering four functional modules, namely, the heterogenous CYP/CPR, MVA, acetyl-CoA generation, and redox cofactor supply modules. First, by screening 25 combinations of cytochrome P450 monooxygenases (CYPs) and NADPH-cytochrome P450 reductases (CPRs), each of which originated from 5 different sources, we selected two optimal betulinic acid-producing strains. Then, ERG1, ERG9, and HMG1 in the MVA module were overexpressed in the two strains, which dramatically increased betulinic acid production and resulted in a strain (YLJCC56) that exhibited the highest betulinic acid yield of 51.87 ± 2.77 mg/L. Then, we engineered the redox cofactor supply module by introducing NADPH- or NADH-generating enzymes and the acetyl-CoA generation module by directly overexpressing acetyl-CoA synthases or reinforcing the ß-oxidation pathway, which further increased the total triterpenoid yield (the sum of the betulin, betulinic acid, betulinic aldehyde yields). Finally, we engineered these modules in combination, and the total triterpenoid yield reached 204.89 ± 11.56 mg/L (composed of 65.44% betulin, 23.71% betulinic acid and 10.85% betulinic aldehyde) in shake flask cultures. CONCLUSIONS: Here, we systematically engineered Y. lipolytica and achieved, to the best of our knowledge, the highest betulinic acid and total triterpenoid yields reported in microbes. Our study provides a suitable reference for studies on heterologous exploitation of P450 enzymes and manipulation of triterpenoid production in Y. lipolytica.

Li2CsB7O10(OH)4: A Deep-Ultraviolet Nonlinear-Optical Mixed-Alkaline Borate Constructed by Unusual Heptaborate Anions.

A new noncentrosymmetric mixed-alkaline borate, Li2CsB7O10(OH)4 (1), was made under solvothermal conditions. This layered boron oxide framework consists of unique bird-shaped [B7O12(OH)4]7- clusters with large 14-ring pores. Its second-harmonic-generation (SHG) signal is 2.5KDP (KH2PO4), with its short ultraviolet (UV) cutoff edge indicating that this crystal is a potential deep-UV transparent nonlinear-optical material.

One View Per City for Buildings Segmentation in Remote-Sensing Images via Fully Convolutional Networks: A Proof-of-Concept Study.

The segmentation of buildings in remote-sensing (RS) images plays an important role in monitoring landscape changes. Quantification of these changes can be used to balance economic and environmental benefits and most importantly, to support the sustainable urban development. Deep learning has been upgrading the techniques for RS image analysis. However, it requires a large-scale data set for hyper-parameter optimization. To address this issue, the concept of "one view per city" is proposed and it explores the use of one RS image for parameter settings with the purpose of handling the rest images of the same city by the trained model. The proposal of this concept comes from the observation that buildings of a same city in single-source RS images demonstrate similar intensity distributions. To verify the feasibility, a proof-of-concept study is conducted and five fully convolutional networks are evaluated on five cities in the Inria Aerial Image Labeling database. Experimental results suggest that the concept can be explored to decrease the number of images for model training and it enables us to achieve competitive performance in buildings segmentation with decreased time consumption. Based on model optimization and universal image representation, it is full of potential to improve the segmentation performance, to enhance the generalization capacity, and to extend the application of the concept in RS image analysis.

Small-world indices via network efficiency for brain networks from diffusion MRI.

The small-world architecture has gained considerable attention in anatomical brain connectivity studies. However, how to adequately quantify small-worldness in diffusion networks has remained a problem. We addressed the limits of small-world measures and defined new metric indices: the small-world efficiency (SWE) and the small-world angle (SWA), both based on the tradeoff between high global and local efficiency. To confirm the validity of the new indices, we examined the behavior of SWE and SWA of networks based on the Watts-Strogatz model as well as the diffusion tensor imaging (DTI) data from 75 healthy old subjects (aged 50-70). We found that SWE could classify the subjects into different age groups, and was correlated with individual performance on the WAIS-IV test. Moreover, to evaluate the sensitivity of the proposed measures to network, two network attack strategies were applied. Our results indicate that the new indices outperform their predecessors in the analysis of DTI data.

Impact of Magnetic Resonance Imaging on Treatment-Related Decision Making for Osteoporotic Vertebral Compression Fracture: A Prospective Randomized Trial.

BACKGROUND The aim of this study was to analyze the impact and usefulness of characteristic signal change of a linear black signal on magnetic resonance imaging (MRI) on treatment-related decision making. MATERIAL AND METHODS Forty-one patients with a linear black signal on MRI were enrolled in this prospective study. They were randomly divided into the percutaneous kyphoplasty (PKP) group (n=24) and the conservative treatment group (n=17). Clinical measures, including visual analog scale (VAS) and short-form 36 (SF-36) questionnaire, were analyzed. Radiographic measures, including anterior vertebral body height, kyphosis angle and rate of bone-union, were evaluated. RESULTS VAS scores were significantly lower in the PKP group than in the conservative treatment group post-treatment and at one-year follow-up. After one year of treatment, the values for physical functioning, physical health, and body pain were significantly higher in the PKP group than in the conservative treatment group (p<0.05). The PKP group had a significantly higher anterior vertebral body height, rate of bone-union, and lower kyphosis angle than the conservative treatment group at one-year follow-up (p<0.05). CONCLUSIONS In patients with a linear black signal detected on MRI, the first-choice treatment should be PKP rather than conservative treatment.

An orally administered DNA vaccine targeting vascular endothelial growth factor receptor-3 inhibits lung carcinoma growth.

Lung cancer is the leading cause of mortality and 5-year survival rate is very low worldwide. Recent studies show that vascular endothelial growth factor receptor-3 (VEGFR-3) signaling pathway contributes to lung cancer progression. So we hypothesize that an oral DNA vaccine that targets VEGFR-3 carried by attenuated Salmonella enterica serovar typhimurium strain SL3261 has impacts on lung cancer progression. In this study, the oral VEGFR-3-based vaccine-immunized mice showed appreciable inhibition of tumor growth and tumor lymphatic microvessels in lung cancer mice model. Moreover, the oral VEGFR-3-based vaccine-immunized mice showed remarkable increases in both VEGFR-3-specific antibody levels and cytotoxic activity. Furthermore, the oral VEGFR-3-based vaccine-immunized mice showed a significant increase in the levels of T helper type 1 (Th1) cell intracellular cytokine expression (IL-2, IFN-γ, and TNF-α). After inoculation with murine Lewis lung carcinoma (LLC) cells, CD4(+) or CD8(+) T cell numbers obviously declined in control groups whereas high levels were maintained in the oral VEGFR-3-based vaccine group. These results demonstrated that the oral VEGFR-3-based vaccine could induce specific humoral and cellular immune responses and then significantly inhibit lung carcinoma growth via suppressing lymphangiogenesis.

Sequential Nanopatterned Block Copolymer Self-Assembly on Surfaces.

Bottom-up self-assembly of high-density block-copolymer nanopatterns is of significant interest for a range of technologies, including memory storage and low-cost lithography for on-chip applications. The intrinsic or native spacing of a given block copolymer is dependent upon its size (N, degree of polymerization), composition, and the conditions of self-assembly. Polystyrene-block-polydimethylsiloxane (PS-b-PDMS) block copolymers, which are well-established for the production of strongly segregated single-layer hexagonal nanopatterns of silica dots, can be layered sequentially to produce density-doubled and -tripled nanopatterns. The center-to-center spacing and diameter of the resulting silica dots are critical with respect to the resulting double- and triple-layer assemblies because dot overlap reduces the quality of the resulting pattern. The addition of polystyrene (PS) homopolymer to PS-b-PDMS reduces the size of the resulting silica dots but leads to increased disorder at higher concentrations. The quality of these density-multiplied patterns can be calculated and predicted using parameters easily derived from SEM micrographs of corresponding single and multilayer patterns; simple geometric considerations underlie the degree of overlap of dots and layer-to-layer registration, two important factors for regular ordered patterns, and clearly defined dot borders. Because the higher-molecular-weight block copolymers tend to yield more regular patterns than smaller block copolymers, as defined by order and dot circularity, this sequential patterning approach may provide a route toward harnessing these materials, thus surpassing their native feature density.

Acquired resistance to HSP90 inhibitor 17-AAG and increased metastatic potential are associated with MUC1 expression in colon carcinoma cells.

Heat shock protein 90 (HSP90) is a molecular chaperone required for the stability and function of many proteins. The chaperoning of oncoproteins by HSP90 enhances the survival, growth, and invasive potential of cancer cells. HSP90 inhibitors are promising new anticancer agents, in which the benzoquinone ansamycin 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in clinical evaluation. However, the implications of acquired resistance to this class of drug remain largely unexplored. In the present study, we have generated isogenic human colon cancer cell lines that are resistant to 17-AAG by continued culturing in the compound. Cross-resistance was found with another HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin. The resistant cells showed obvious morphology changes with a metastatic phenotype and significant increases in migration and adhesion to collagens. Western blotting analysis of epithelial-mesenchymal transition molecular markers found that expression of E-cadherin downregulated, whereas expression of N-cadherin and ß-catenin upregulated in the resistant cells. Mucin 1 (MUC1) has been reported to mediate metastasis as well as chemical resistance in many cancers. Here, we found that MUC1 expression was significantly elevated in the acquired drug resistance cells. 17-AAG treatment could decrease MUC1 more in parental cells than in acquired 17-AAG-resistant cells. Further study found that knockdown of MUC1 expression by small interfering RNA could obviously re-sensitize the resistant cells to 17-AAG treatment, and decrease the cell migration and adhesion. These were coupled with a downregulation in N-cadherin and ß-catenin. The results indicate that HSP90 inhibitor therapies in colon carcinomas could generate resistance and increase metastatic potential that might mediated by upregulation of MUC1 expression. Findings from this study further our understanding of the potential clinical effects of HSP90-directed therapies in colon carcinomas.

SFTS virus infection in nonhuman primates.

SFTS virus (SFTSV) is a highly pathogenic bunyavirus that causes severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease in China. Laboratory mice have been reported to be susceptible to SFTSV infection, but the infection in nonhuman primates has not been investigated. This study is the first to report that, in rhesus macaques, SFTSV does not cause severe symptoms or death but causes fever, thrombocytopenia, leukocytopenia, and increased levels of transaminases and myocardial enzymes in blood. Viremia, virus-specific immunoglobulin M and immunoglobulin G antibodies, and neutralizing antibodies were identified in all infected macaques. Levels of the cytokines interferon γ, eotaxin, tumor necrosis factor α, and macrophage inflammatory protein 1ß were significantly elevated in the blood. Minor pathological lesions were observed in the liver and kidney during the late stages of infection. Overall, SFTSV infection in rhesus macaques resembled mild SFTS in humans.

Genome-wide analysis of WRKY transcription factors in white pear (Pyrus bretschneideri) reveals evolution and patterns under drought stress.

BACKGROUND: WRKY transcription factors (TFs) constitute one of the largest protein families in higher plants, and its members contain one or two conserved WRKY domains, about 60 amino acid residues with the WRKYGQK sequence followed by a C2H2 or C2HC zinc finger motif. WRKY proteins play significant roles in plant development, and in responses to biotic and abiotic stresses. Pear (Pyrus bretschneideri) is one of the most important fruit crops in the world and is frequently threatened by abiotic stress, such as drought, affecting growth, development and productivity. Although the pear genome sequence has been released, little is known about the WRKY TFs in pear, especially in respond to drought stress at the genome-wide level. RESULTS: We identified a total of 103 WRKY TFs in the pear genome. Based on the structural features of WRKY proteins and topology of the phylogenetic tree, the pear WRKY (PbWRKY) family was classified into seven groups (Groups 1, 2a-e, and 3). The microsyteny analysis indicated that 33 (32%) PbWRKY genes were tandemly duplicated and 57 genes (55.3%) were segmentally duplicated. RNA-seq experiment data and quantitative real-time reverse transcription PCR revealed that PbWRKY genes in different groups were induced by drought stress, and Group 2a and 3 were mainly involved in the biological pathways in response to drought stress. Furthermore, adaptive evolution analysis detected a significant positive selection for Pbr001425 in Group 3, and its expression pattern differed from that of other members in this group. The present study provides a solid foundation for further functional dissection and molecular evolution of WRKY TFs in pear, especially for improving the water-deficient resistance of pear through manipulation of the PbWRKYs.

Pathogenesis of emerging severe fever with thrombocytopenia syndrome virus in C57/BL6 mouse model.

The discovery of an emerging viral disease, severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV), has prompted the need to understand pathogenesis of SFTSV. We are unique in establishing an infectious model of SFTS in C57/BL6 mice, resulting in hallmark symptoms of thrombocytopenia and leukocytopenia. Viral RNA and histopathological changes were identified in the spleen, liver, and kidney. However, viral replication was only found in the spleen, which suggested the spleen to be the principle target organ of SFTSV. Moreover, the number of macrophages and platelets were largely increased in the spleen, and SFTSV colocalized with platelets in cytoplasm of macrophages in the red pulp of the spleen. In vitro cellular assays further revealed that SFTSV adhered to mouse platelets and facilitated the phagocytosis of platelets by mouse primary macrophages, which in combination with in vivo findings, suggests that SFTSV-induced thrombocytopenia is caused by clearance of circulating virus-bound platelets by splenic macrophages. Thus, this study has elucidated the pathogenic mechanisms of thrombocytopenia in a mouse model resembling human SFTS disease.

Increased L-arginine Production by Site-directed Mutagenesis of N-acetyl-L-glutamate Kinase and proB Gene Deletion in Corynebacterium crenatum.

OBJECTIVE: In Corynebacterium crenatum, the adjacent D311 and D312 of N-acetyl-L-glutamate kinase (NAGK), as a key rate-limiting enzyme of L-arginine biosynthesis under substrate regulatory control by arginine, were initially replaced with two arginine residues to investigate the L-arginine feedback inhibition for NAGK. METHODS: NAGK enzyme expression was evaluated using a plasmid-based method. Homologous recombination was employed to eliminate the proB. RESULTS: The IC50 and enzyme activity of NAGK M4, in which the D311R and D312R amino acid substitutions were combined with the previously reported E19R and H26E substitutions, were 3.7-fold and 14.6% higher, respectively, than those of the wild-type NAGK. NAGK M4 was successfully introduced into the C. crenatum MT genome without any genetic markers; the L-arginine yield of C. crenatum MT-M4 was 26.2% higher than that of C. crenatum MT. To further improve upon the L-arginine yield, we constructed the mutant C. crenatum MT-M4 proB. The optimum concentration of L-proline was also investigated in order to determine its contribution to L-arginine yield. After L-proline was added to the medium at 10 mmol/L, the L-arginine yield reached 16.5 g/L after 108 h of shake-flask fermentation, approximately 70.1% higher than the yield attained using C. crenatum MT. CONCLUSION: Feedback inhibition of L-arginine on NAGK in C. crenatum is clearly alleviated by the M4 mutation of NAGK, and deletion of the proB in C. crenatum from MT to M4 results in a significant increase in arginine production.

Structure of severe fever with thrombocytopenia syndrome virus nucleocapsid protein in complex with suramin reveals therapeutic potential.

Severe fever with thrombocytopenia syndrome is an emerging infectious disease caused by a novel bunyavirus (SFTSV). Lack of vaccines and inadequate therapeutic treatments have made the spread of the virus a global concern. Viral nucleocapsid protein (N) is essential for its transcription and replication. Here, we present the crystal structures of N from SFTSV and its homologs from Buenaventura (BUE) and Granada (GRA) viruses. The structures reveal that phleboviral N folds into a compact core domain and an extended N-terminal arm that mediates oligomerization, such as tetramer, pentamer, and hexamer of N assemblies. Structural superimposition indicates that phleboviral N adopts a conserved architecture and uses a similar RNA encapsidation strategy as that of RVFV-N. The RNA binding cavity runs along the inner edge of the ring-like assembly. A triple mutant of SFTSV-N, R64D/K67D/K74D, almost lost its ability to bind RNA in vitro, is deficient in its ability to transcribe and replicate. Structural studies of the mutant reveal that both alterations in quaternary assembly and the charge distribution contribute to the loss of RNA binding. In the screening of inhibitors Suramin was identified to bind phleboviral N specifically. The complex crystal structure of SFTSV-N with Suramin was refined to a 2.30-Å resolution. Suramin was found sitting in the putative RNA binding cavity of SFTSV-N. The inhibitory effect of Suramin on SFTSV replication was confirmed in Vero cells. Therefore, a common Suramin-based therapeutic approach targeting SFTSV-N and its homologs could be developed for containing phleboviral outbreaks.

Histamine in the locus coeruleus promotes descending noradrenergic inhibition of neuropathic hypersensitivity.

Among brain structures receiving efferent projections from the histaminergic tuberomammillary nucleus is the pontine locus coeruleus (LC) involved in descending noradrenergic control of pain. Here we studied whether histamine in the LC is involved in descending regulation of neuropathic hypersensitivity. Peripheral neuropathy was induced by unilateral spinal nerve ligation in the rat with a chronic intracerebral and intrathecal catheter for drug administrations. Mechanical hypersensitivity in the injured limb was assessed by monofilaments. Heat nociception was assessed by determining radiant heat-induced paw flick. Histamine in the LC produced a dose-related (1-10µg) mechanical antihypersensitivity effect (maximum effect at 15min and duration of effect 30min), without influence on heat nociception. Pretreatment of LC with zolantidine (histamine H2 receptor antagonist), but not with pyrilamine (histamine H1 receptor antagonist), and spinal administration of atipamezole (an α2-adrenoceptor antagonist), prazosine (an α1-adrenoceptor antagonist) or bicuculline (a GABAA receptor antagonist) attenuated the antihypersensitivity effect of histamine. The histamine-induced antihypersensitivity effect was also reduced by pretreatment of LC with fadolmidine, an α2-adrenoceptor agonist inducing autoinhibition of noradrenergic cell bodies. Zolantidine or pyrilamine alone in the LC failed to influence pain behavior, while A-960656 (histamine H3 receptor antagonist) suppressed hypersensitivity. A plausible explanation for these findings is that histamine, due to excitatory action mediated by the histamine H2 receptor on noradrenergic cell bodies, promotes descending spinal α1/2-adrenoceptor-mediated inhibition of neuropathic hypersensitivity. Blocking the autoinhibitory histamine H3 receptor on histaminergic nerve terminals in the LC facilitates release of histamine and thereby, increases descending noradrenergic pain inhibition.