A Novel Murine Model Expressing a Chimeric mSCARB2/hSCARB2 Receptor Is Highly Susceptible to Oral Infection with Clinical Isolates of Enterovirus 71.

Enterovirus 71 (EV71) infection is generally associated with hand-foot-and-mouth disease (HFMD) and may cause severe neurological disorders and even death. An effective murine oral infection model for studying the pathogenesis of various clinical EV71 isolates is lacking. We developed a transgenic (Tg) mouse that expresses an EV71 receptor, that is, human scavenger receptor class B member 2 (hSCARB2), in a pattern highly similar to that of endogenous murine SCARB2 (mSCARB2) protein. A FLAG-tagged SCARB2 cDNA fragment composed of exons 3 to 12 was inserted into a murine Scarb2 gene-containing bacterial artificial chromosome (BAC) clone, and the resulting transgene was used for establishment of chimeric receptor-expressing Tg mice. Tg mice intragastrically (i.g.) infected with clinical isolates of EV71 showed neurological symptoms, such as ataxia and paralysis, and fatality. There was an age-dependent decrease in susceptibility to viral infection. Pathological characteristics of the infected Tg mice resembled those of encephalomyelitis in human patients. Viral infection was accompanied by microglial activation. Clodronate treatment of the brain slices from Tg mice enhanced viral replication, while lipopolysaccharide treatment significantly inhibited it, suggesting an antiviral role for microglia during EV71 infection. Taken together, this Tg mouse provides a model that closely mimics natural infection for studying EV71 pathogenesis and for evaluating the efficacy of vaccines or other antiviral drugs.IMPORTANCE The availability of a murine model of EV71 infection is beneficial for the understanding of pathogenic mechanisms and the development and assessment of vaccines and antiviral drugs. However, the lack of a murine oral infection model thwarted the study of pathogenesis induced by clinically relevant EV71 strains that are transmitted via the oral-oral or oral-fecal route. Our Tg mice could be intragastrically infected with clinically relevant EV71 strains in an efficient way and developed neurological symptoms and pathological changes strikingly resembling those of human infection. Moreover, these mice showed an age-dependent change in susceptibility that is similar to the human case. This Tg mouse, when combined with the use of other genetically modified mice, potentially contributes to studying the relationship between developmental changes in immunity and susceptibility to virus.

Fatty acids and small organic compounds bind to mineralo-organic nanoparticles derived from human body fluids as revealed by metabolomic analysis.

Nanoparticles entering the human body instantly become coated with a "protein corona" that influences the effects and distribution of the particles in vivo. Yet, whether nanoparticles may bind to other organic compounds remains unclear. Here we use an untargeted metabolomic approach based on ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry to identify the organic compounds that bind to mineral nanoparticles formed in human body fluids (serum, plasma, saliva, and urine). A wide range of organic compounds is identified, including fatty acids, glycerophospholipids, amino acids, sugars, and amides. Our results reveal that, in addition to the proteins identified previously, nanoparticles harbor an "organic corona" containing several fatty acids which may affect particle-cell interactions in vivo. This study provides a platform to study the organic corona of biological and synthetic nanoparticles found in the human body.

A copper-based layered coordination polymer: synthesis, magnetic properties and electrochemical performance in supercapacitors.

A copper-based layered coordination polymer ([Cu(hmt)(tfbdc)(H2O)]; hmt = hexamethylenetetramine, tfbdc = 2,3,5,6-tetrafluoroterephthalate; Cu-LCP) has been synthesized, and it has been structurally and magnetically characterized. The Cu-LCP shows ferromagnetic interactions between the adjacent copper(II) ions. Density functional theory calculations on the special model of Cu-LCP support the occurrence of ferromagnetic interactions. As an electrode material for supercapacitors, Cu-LCP exhibits a high specific capacitance of 1274 F g(-1) at a current density of 1 A g(-1) in 1 M LiOH electrolyte, and the capacitance retention is about 88% after 2000 cycles.

Distinct patterns of the lipid alterations between genotype 1 and 2 chronic hepatitis C patients after viral clearance.

BACKGROUND: The hepatitis C virus (HCV) genotype-specific impacts on the host metabolic alterations remained inconclusive. METHODS: A prospective study including 229 (118 genotype 1 (G1) and 111 G2) consecutive chronic HCV patients who had completed a course of anti-HCV treatment and underwent pre- and 24 weeks post-treatment surveys of metabolic profiles was conducted. Patients were stratified according to the therapeutic response, viral genotype and baseline insulin resistance (IR: homeostasis model assessments of IR (HOMA-IR) ≥ 2.5). Paired t-tests were used to compare the pre- and post-treatment variables. RESULTS: Significant post-therapeutic increases in cholesterol, triglyceride, HDL, LDL, apolipoprotein A1 and apolipoprotein B were observed in patients with sustained virological response (SVR) but not in those without. Among those with SVR, post-therapeutic increases in HDL (p<0.001) and apolipoprotein A1 (p = 0.012) were only found in G2, whereas increased triglyceride/HDL (p = 0.01) ratios were only found in G1 patients. When stratified by baseline IR among those with SVR, a significant increase in post-treatment HDL (p = 0.019) and apolipoprotein A1 (p = 0.012) but a decrease in HOMA-IR (p = 0.04), C-peptide (p = 0.019) and hemoglobin A1c (p = 0.047) were found in patients with baseline IR; a significant increase in HOMA-IR (p = 0.002) was found in patients without baseline IR. The latter change was observed only in G1 (p = 0.01) but not G2 patients. Although the pre-treatment metabolic profiles of G1 and G2 patients were indifferent, G1 had higher post-treatment triglyceride/HDL ratios (p = 0.041) and triglyceride (p = 0.044) levels than G2 patients. CONCLUSIONS: G2 benefit more than G1 patients from viral clearance in metabolic alterations, particularly in those without baseline IR.

Functional expression of phaCAB genes from Cupriavidus taiwanensis strain 184 in Escherichia coli for polyhydroxybutyrate production.

Polyhydroxyalkanoates are polyesters synthesized by numerous microorganisms. These polyesters are biodegradable and have similar properties to those of conventional plastics. Cupriavidus taiwanensis strain 184 is phylogenetically related to the well-known polyhydroxybutyrate (PHB) producer Ralstonia eutropha (Cupriavidus necator) and is also shown to be able to accumulate significant amounts of PHB. In this study, we cloned the PHB synthesis genes (phaCAB) from C. taiwanensis 184 into Escherichia coli for biosynthesis of PHB. The recombinant E. coli strains were able to synthesize significant amounts of PHB. The PHB amounted to about 66~70% of total cell material of these recombinant strains.