Portable Self-Powered/Colorimetric Dual-Mode Sensing Platform Based on Multifunctional Bioconjugates for Precise On-Site Detection of Acetamiprid.

Neonicotinoid insecticides have been widely applied in modern agriculture to improve crop productivity, but their residues have adverse impacts on the environment and human health. Hence, to address these issues, a portable self-powered/colorimetric dual-mode sensing platform was developed for the simple, rapid, precise, and sensitive on-site detection of acetamiprid (ATM) residues in vegetables. In this case, a multifunctional bioconjugate with specific recognition capability, excellent enzyme-like activity, and loading capacity is the key to the sensing design.

Widespread photosynthesis reaction centre barrel proteins are necessary for haloarchaeal cell division.

Cell division is fundamental to all cellular life. Most archaea depend on either the prokaryotic tubulin homologue FtsZ or the endosomal sorting complex required for transport for division but neither system has been robustly characterized. Here, we show that three of the four photosynthesis reaction centre barrel domain proteins of Haloferax volcanii (renamed cell division proteins B1/2/3 (CdpB1/2/3)) play important roles in cell division.

miRNA profiling of granulosa cell-derived exosomes reveals their role in promoting follicle development.

To explore whether granulosa cell (GC)-derived exosomes (GC-Exos) and follicular fluid-derived exosomes (FF-Exos) have functional similarities in follicle development and to establish relevant experiments to validate whether GC-Exos could serve as a potential substitute for follicular fluid-derived exosomes to improve folliculogenesis. GC-Exos were characterized. MicroRNA (miRNA) profiles of exosomes from human GCs and follicular fluid were analyzed in depth.

Widespread PRC barrel proteins play critical roles in archaeal cell division.

Cell division is fundamental to all cellular life. Most of the archaea employ one of two alternative division machineries, one centered around the prokaryotic tubulin homolog FtsZ and the other around the endosomal sorting complex required for transport (ESCRT). However, neither of these mechanisms has been thoroughly characterized in archaea.

Coinfection with influenza A virus enhances SARS-CoV-2 infectivity.

The upcoming flu season in the Northern Hemisphere merging with the current COVID-19 pandemic raises a potentially severe threat to public health. Through experimental coinfection with influenza A virus (IAV) and either pseudotyped or live SARS-CoV-2 virus, we found that IAV preinfection significantly promoted the infectivity of SARS-CoV-2 in a broad range of cell types. Remarkably, in vivo, increased SARS-CoV-2 viral load and more severe lung damage were observed in mice coinfected with IAV.

Pathways of cholesterol homeostasis in mouse retina responsive to dietary and pharmacologic treatments.

Effects of serum cholesterol on cholesterol content in the retina are currently unknown. It is also unclear how cholesterol levels are controlled in the retina. High-cholesterol diet and oral administrations of simvastatin were used to modulate serum cholesterol in mice.

Retinal and nonocular abnormalities in Cyp27a1(-/-)Cyp46a1(-/-) mice with dysfunctional metabolism of cholesterol.

Cholesterol elimination from nonhepatic cells involves metabolism to side-chain oxysterols, which serve as transport forms of cholesterol and bioactive molecules modulating a variety of cellular processes. Cholesterol metabolism is tissue specific, and its significance has not yet been established for the retina, where cytochromes P450 (CYP27A1 and CYP46A1) are the major cholesterol-metabolizing enzymes. We generated Cyp27a1(-/-)Cyp46a1(-/-) mice, which were lean and had normal serum cholesterol and glucose levels.

Antifungal Azoles: Structural Insights into Undesired Tight Binding to Cholesterol-Metabolizing CYP46A1.

Although there are currently three generations of antifungal azoles on the market, even the third-generation agents show undesirable interactions with human cytochrome P450 (P450) enzymes. CYP46A1 is a cholesterol-metabolizing P450 in the brain that tightly binds a number of structurally distinct azoles. Previously, we determined the crystal structures of CYP46A1 in complex with voriconazole and clotrimazole, and in the present work we cocrystallized the P450 with posaconazole at 2.

Stimulation of mouse Cyp1b1 during adipogenesis: characterization of promoter activation by the transcription factor Pax6.

Cytochrome P4501B1 (Cyp1b1) is expressed specifically in certain neural crest (NC) cells during embryogenesis. Mesenchymal progenitor cells that develop from NC cells are modeled here by mouse C3H10T1/2 and 3T3-L1 cells. Dexamethasone in combination with methylisobutylxanthine (DM) induces Cyp1b1 and a 6.

Binding of a cyano- and fluoro-containing drug bicalutamide to cytochrome P450 46A1: unusual features and spectral response.

Cytochrome P450 46A1 (CYP46A1) is the cholesterol 24-hydroxylase initiating the major pathways of cholesterol removal from the brain, and bicalutamide (BIC) is a drug of choice for the treatment of progressive androgen-dependent prostate cancer. We evaluated the interactions of BIC with CYP46A1 by x-ray crystallography and by conducting solution and mutagenesis studies. Because BIC is administered to patients as a racemic mixture of the S and R isomers, we studied all three, racemic BIC as well as the S and R isomers.

Abnormal vascularization in mouse retina with dysregulated retinal cholesterol homeostasis.

Several lines of evidence suggest a link between age-related macular degeneration and retinal cholesterol maintenance. Cytochrome P450 27A1 (CYP27A1) is a ubiquitously expressed mitochondrial sterol 27-hydroxylase that plays an important role in the metabolism of cholesterol and cholesterol-related compounds. We conducted a comprehensive ophthalmic evaluation of mice lacking CYP27A1.

Spatial distribution of the pathways of cholesterol homeostasis in human retina.

Background: The retina is a light-sensitive tissue lining the inner surface of the eye and one of the few human organs whose cholesterol maintenance is still poorly understood. Challenges in studies of the retina include its complex multicellular and multilayered structure; unique cell types and functions; and specific physico-chemical environment.

Methodology/principal Findings: We isolated specimens of the neural retina (NR) and underlying retinal pigment epithelium (RPE)/choroid from six deceased human donors and evaluated them for expression of genes and proteins representing the major pathways of cholesterol input, output and regulation.

Marked variability in hepatic expression of cytochromes CYP7A1 and CYP27A1 as compared to cerebral CYP46A1. Lessons from a dietary study with omega 3 fatty acids in hamsters.

Two diets simulating the recommendations of the American Heart Association to increase the intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) were tested on Golden Syrian hamsters and compared to the diet simulating the current estimated consumption of fat in the United States. N-3 PUFAs were evaluated for their effects on serum and brain lipids and on the three cytochrome P450 enzymes (CYPs 7A1, 27A1, and 46A1) that play key roles in cholesterol elimination from different organs. Hamsters on the highest concentration of n-3 PUFAs had a statistically significant decrease in LDL and HDL cholesterol and no change in serum total cholesterol and triglycerides levels.

Binding of steroidogenic factor-1 to the regulatory region might not be critical for transcriptional regulation of the human CYP1B1 gene.

Cytochrome P450 (CYP) 1B1, which catalyzes 17beta-estradiol 4-hydroxylation, is expressed in steroid-related tissues including ovary, testis, and adrenal gland. Generally, the expressions of steroidogenic CYPs are transcriptionally regulated by steroidogenic factor-1 (SF-1) and cAMP response element (CRE) binding protein (CREB). In the present study, we examined the possibility that the human CYP1B1 gene might be regulated by SF-1 and CREB.

Differentiation of pluripotent C3H10T1/2 cells rapidly elevates CYP1B1 through a novel process that overcomes a loss of Ah Receptor.

Stimulation of C3H10T1/2 cells by an adipogenic hormonal mixture (IDM) consisting of insulin (I), dexamethasone (D), and methylisobutylxanthine (M) substantially induces cytochrome P450 (CYP) 1B1 expression. This stimulation represents up to 40% of the level produced by maximum activation of the arylhydrocarbon receptor (AhR) with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Dexamethasone and methylisobutylxanthine in combination produced near maximum elevation of CYP1B1 along with a subsequent decline in AhR that paralleled the rise in peroxisome proliferator-activated receptorgamma1 (PPARgamma1).

Identification of novel TCDD-regulated genes by microarray analysis.

TCDD exposure of multipotential C3H10T1/2 fibroblasts for 72 h altered the expression of over 1000 genes, including coordinated changes across large functionally similar gene clusters. TCDD coordinately induced 23 cell cycle-related genes similar to epidermal growth factor (EGF)-induced levels but without any affect on the major mitogenic signaling pathway (extracellular signal-regulated kinase, ERK). TCDD treatment also decreased glycolytic and ribosomal clusters.

Steroidogenic factor-1 interacts with cAMP response element-binding protein to mediate cAMP stimulation of CYP1B1 via a far upstream enhancer.

CYP1B1 activates polycyclic aromatic hydrocarbon carcinogens in cAMP-regulated tissues such as the adrenal, ovary, and testis. A 27-fold cAMP stimulation of the CYP1B1-luciferase reporter in Y-1 adrenal cells depends entirely on a far upstream enhancer region (FUER; -5298 to -5110). Cooperative participation of multiple steroidogenic factor 1 (SF-1) elements with the downstream cAMP response element (CRE) in FUER is essential for both basal and cAMP-stimulated activities of FUER.

Disruption of cell-cell contact maximally but transiently activates AhR-mediated transcription in 10T1/2 fibroblasts.

The aryl hydrocarbon receptor (AhR) is activated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but activation without an exogenous ligand also occurs when normal cell-cell contact is prevented. Suspension of several C3H10T1/2 fibroblast clonal sub-lines that contain an integrated AhR-responsive reporter produced a time course and level of reporter activation and CYP1B1 induction that paralleled TCDD stimulation in confluent monolayer culture. Suspension activation was, however, more transient.

Ah receptor regulation of mouse Cyp1B1 is additionally modulated by a second novel complex that forms at two AhR response elements.

Cyp1B1 is expressed constitutively in many extrahepatic cells and is induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). An enhancer region (AhER-810 to -1075 of the mouse Cyp1B1 promoter), which mediates aryl hydrocarbon receptor (AhR) regulation of transcription, contains three consensus XRE sequences (designated XRE1, XRE4, and XRE5) and a central Ebox. XRE5 is essential for both basal and induced activity in C3H10T1/2 cells.

tRNA-embedded Hammerhead Ribozymes Mediate Destruction of HBV (Subtype adr) in vitro.

Two hammerhead ribozymes, RS3 and RC2, targeting the HBsAg and HBcAg regions of HBV (adr) RNA respectively, have been designed. To improve the stability of ribozymes, two tRNA-embedded ribozymes, RtS3 and RtC2, were obtained by inserting RS3 and RC2 into the anticodon region of tRNA. Although the catalytic activity of the tRNA-embedded ribozymes was lower than that of their naked counterparts, the stability of the former in fetal bovine serum or cytoplasmic extract of HepG2 cells was much higher than that of the naked ribozymes.

Hammerhead Ribozymes Suppress HBV(adr) in HepG2 Cells.

Three hammerhead ribozymes (RS3, RC2 and RC1) targeting to the HBV genome have been designed. Plasmids were constructed by inserting the genes of naked and tRNA-embedded ribozymes into RNA trimming vector pRG523 and then were transferred to eukaryotic expression vector. By the similar cloning method the shotgun-type plasmids carrying homogeneous RS3 or RtS3 unitconnected in tandem were obtained.