A total synthesis strategy was developed for the synthesis of luotonin A, B and their analogues using synergistic FeCl3/KI‐catalyzed oxidative cyclization. This protocol utilizes cheap and widely ...available N‐propargyl 2‐methyl‐quinazolinones and arylamines under mild conditions, and it has a wide substrate scope and high atom economy. Different natural products (luotonin A, B and derivatives) can be synthesized via a unique switchable approach. Further transformations from luotonin B to luotonin E and structural modification of natural products demonstrate the potential applications of this method. Moreover, camptothecin can also be modified with the reported protocol to afford the hydroxyl‐substituted product.
Exosomes are cell-derived vesicles and are abundant in biological fluids; they contain RNA molecules which may serve as potential diagnostic biomarkers in 'precision medicine'. To promote the ...clinical application of exosomal RNA (exoRNA), many isolation methods must be compared and validated. Exosomes in cell culture medium (CCM) and serum may be isolated using ultracentrifugation (UC), ExoQuick or Total Exosome Isolation Reagent (TEI), and exoRNA may be extracted using TRIzol-LS, SeraMir, Total Exosome RNA Isolation (TER), HiPure Liquid RNA/miRNA kit (HLR), miRNeasy or exoRNeasy. ExoRNA was assessed using NanoDrop, Bioanalyzer 2100, quantitative polymerase chain reaction and high-throughput sequencing. UC showed the lowest recovery of particles, but the highest protein purity for exosome isolation. For isolation of exoRNA, we found that combinations of the TEI and TER methods resulted in high extraction efficiency and purity of small RNA obtained using CCM. High yield and a narrow size distribution pattern of small RNA were shown in exoRNA isolated by exoRNeasy from serum. In RNA profile analysis, the small RNA constituent ratio, miRNA content and amount varied as a result of methodological differences. This study showed that different methods may introduce variations in the concentration, purity and size of exosomes and exoRNA. Herein we discuss the advantages and disadvantages of each method and their application to different materials, therefore providing a reference according to research design.
The human gut microbiome can modulate metabolic health and affect insulin resistance, and it may play an important role in the etiology of gestational diabetes mellitus (GDM). Here, we compared the ...gut microbial composition of 43 GDM patients and 81 healthy pregnant women via whole-metagenome shotgun sequencing of their fecal samples, collected at 21–29 weeks, to explore associations between GDM and the composition of microbial taxonomic units and functional genes. A metagenome-wide association study identified 154 837 genes, which clustered into 129 metagenome linkage groups (MLGs) for species description, with significant relative abundance differences between the 2 cohorts. Parabacteroides distasonis, Klebsiella variicola, etc., were enriched in GDM patients, whereas Methanobrevibacter smithii, Alistipes spp., Bifidobacterium spp., and Eubacterium spp. were enriched in controls. The ratios of the gross abundances of GDM-enriched MLGs to control-enriched MLGs were positively correlated with blood glucose levels. A random forest model shows that fecal MLGs have excellent discriminatory power to predict GDM status. Our study discovered novel relationships between the gut microbiome and GDM status and suggests that changes in microbial composition may potentially be used to identify individuals at risk for GDM.
Insect chemosensory proteins (CSPs) have been proposed to capture and transport hydrophobic chemicals from air to olfactory receptors in the lymph of antennal chemosensilla. They may represent a new ...class of soluble carrier protein involved in insect chemoreception. However, their specific functional roles in insect chemoreception have not been fully elucidated. In this study, we report for the first time three novel CSP genes (AlinCSP1-3) of the alfalfa plant bug Adelphocoris lineolatus (Goeze) by screening the antennal cDNA library. The qRT-PCR examinations of the transcript levels revealed that all three genes (AlinCSP1-3) are mainly expressed in the antennae. Interestingly, these CSP genes AlinCSP1-3 are also highly expressed in the 5(th) instar nymphs, suggesting a proposed function of these CSP proteins (AlinCSP1-3) in the olfactory reception and in maintaining particular life activities into the adult stage. Using bacterial expression system, the three CSP proteins were expressed and purified. For the first time we characterized the types of sensilla in the antennae of the plant bug using scanning electron microscopy (SEM). Immunocytochemistry analysis indicated that the CSP proteins were expressed in the pheromone-sensitive sensilla trichodea and general odorant-sensitive sensilla basiconica, providing further evidence of their involvement in chemoreception. The antennal activity of 55 host-related semiochemicals and sex pheromone compounds in the host location and mate selection behavior of A. lineolatus was investigated using electroantennogram (EAG), and the binding affinities of these chemicals to the three CSPs (AlinCSP1-3) were measured using fluorescent binding assays. The results showed several host-related semiochemicals, (Z)-3-hexen-1-ol, (E)-2-hexen-1-al and valeraldehyde, have a high binding affinity with AlinCSP1-3 and can elicit significant high EAG responses of A. lineolatus antennae. Our studies indicate the three antennae-biased CSPs may mediate host recognition in the alfalfa plant bug A. lineolatus.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Multiaxial fatigue tests were conducted on titanium alloy TC4 tubular specimens.•Six multiaxial fatigue parameters are reviewed and evaluated by the test data.•The multiaxial fatigue behaviors of ...TC4 are investigated.•Suitable multiaxial fatigue model to predict fatigue life of TC4 is chosen.
Both proportional and nonproportional tension–torsion fatigue tests were conducted on titanium alloy TC4 tubular specimens. Six multiaxial fatigue parameters are reviewed and evaluated with life data obtained in the tests. It is found that the effective strain, the maximum shear strain and the Smith–Watson–Topper (SWT) criteria tend to give non-conservative results under nonproportional loading. The shear strain-based critical plane approaches, especially Wu–Hu–Song (WHS) approach show better life prediction abilities. The prediction results based on WHS parameter are all within a factor of two scatter band of the test results.
Environmental ultrafine particulate matter (PM) is capable of inducing airway injury, while the detailed molecular mechanisms remain largely unclear. Here, we demonstrate pivotal roles of autophagy ...in regulation of inflammation and mucus hyperproduction induced by PM containing environmentally persistent free radicals in human bronchial epithelial (HBE) cells and in mouse airways. PM was endocytosed by HBE cells and simultaneously triggered autophagosomes, which then engulfed the invading particles to form amphisomes and subsequent autolysosomes. Genetic blockage of autophagy markedly reduced PM-induced expression of inflammatory cytokines, e.g. IL8 and IL6, and MUC5AC in HBE cells. Mice with impaired autophagy due to knockdown of autophagy-related gene Becn1 or Lc3b displayed significantly reduced airway inflammation and mucus hyperproduction in response to PM exposure in vivo. Interference of the autophagic flux by lysosomal inhibition resulted in accumulated autophagosomes/amphisomes, and intriguingly, this process significantly aggravated the IL8 production through NFKB1, and markedly attenuated MUC5AC expression via activator protein 1. These data indicate that autophagy is required for PM-induced airway epithelial injury, and that inhibition of autophagy exerts therapeutic benefits for PM-induced airway inflammation and mucus hyperproduction, although they are differentially orchestrated by the autophagic flux.
Particulate matter (PM) is able to induce airway epithelial injury, while the detailed mechanisms remain unclear. Here we demonstrated that PM exposure inactivated MTOR (mechanistic target of ...rapamycin kinase), enhanced macroautophagy/autophagy, and impaired lysosomal activity in HBE (human bronchial epithelial) cells and in mouse airway epithelium. Genetic or pharmaceutical inhibition of MTOR significantly enhanced, while inhibition of autophagy attenuated, PM-induced IL6 expression in HBE cells. Consistently, club-cell-specific deletion of Mtor aggravated, whereas loss of Atg5 in bronchial epithelium reduced, PM-induced airway inflammation. Interestingly, the augmented inflammatory responses caused by MTOR deficiency were markedly attenuated by blockage of downstream autophagy both in vitro and in vivo. Mechanistically, the dysregulation of MTOR-autophagy signaling was partially dependent on activation of upstream TSC2, and interacted with the TLR4-MYD88 to orchestrate the downstream NFKB activity and to regulate the production of inflammatory cytokines in airway epithelium. Moreover, inhibition of autophagy reduced the expression of EPS15 and the subsequent endocytosis of PM. Taken together, the present study provides a mechanistic explanation for how airway epithelium localized MTOR-autophagy axis regulates PM-induced airway injury, suggesting that activation of MTOR and/or suppression of autophagy in local airway might be effective therapeutic strategies for PM-related airway disorders.
ACTB: actin beta; AKT: AKT serine/threonine kinase; ALI: air liquid interface; AP2: adaptor related protein complex 2; ATG: autophagy related; BALF: bronchoalveolar lavage fluid; COPD: chronic obstructive pulmonary disease; CXCL: C-X-C motif chemokine ligand; DOX: doxycycline; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; EPS15: epidermal growth factor receptor pathway substrate 15; HBE: human bronchial epithelial; H&E: hematoxylin & eosin; IKK: IKB kinase; IL: interleukin; LAMP2: lysosomal-associated membrane protein 2; LPS: lipopolysaccharide; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MTEC: mouse tracheal epithelial cells; MTOR: mechanistic target of rapamycin kinase; MYD88: MYD88 innate immune signal transduction adaptor; NFKB: nuclear factor of kappa B; NFKBIA: NFKB inhibitor alpha; PM: particulate matter; PtdIns3K: phosphatidylinositol 3-kinase; Rapa: rapamycin; RELA: RELA proto-oncogene, NFKB subunit; SCGB1A1: secretoglobin family 1A member 1; siRNA: small interfering RNAs; SQSTM1: sequestosome 1; TEM: transmission electronic microscopy; TLR4: toll like receptor 4; TSC2: TSC complex subunit 2.
Asthma, a major non‐communicable disease, affects both adults and children and is associated with high morbidity compared with other chronic diseases. The glycolysis‐associated activation of type ...2 helper T (Th2) cells is the critical immunopathological mechanism involved in asthma deterioration. Long‐term use of steroids as a medical treatment for asthma induces side effects and resistance. Pterostilbene (PS), a stilbenoid compound found in blueberry and vines, exhibits antihyperglycemic and anti‐inflammatory properties. Thus, we hypothesized that the modulation of T cell immunity by PS may be an applicable intervention to treat asthma. Airway hyperresponsiveness, interleukin (IL)‐4 and IL‐13 levels, IgE, IgG, pulmonary infiltrated monocytes and eosinophils, and mucosubstances were measured in house dust mite (HDM)‐induced asthmatic mice under PS treatment. Bioenergetic metabolism, PI3K‐mTOR signalling, GATA3 expression and histone acetylation in PS‐treated Th2 cells were investigated. PS improved HDM‐induced pulmonary allergic airway inflammation by inhibiting Th2 cell and eosinophil accumulation in HDM asthmatic mice both in the preventive and therapeutic models. Targeting glycolysis resulted in IL‐4 inhibition via the downregulation of mTOR, GATA3 and histone acetylation in PS‐treated Th2 cells. Glucose supplementation reversed the inhibitory effect of PS on Th2 cells in vitro. Adoptive transfer with glucose‐treated Th2 cells enhanced Th2 activation and eosinophilic accumulation in PS‐treated asthmatic mice. Furthermore, PS significantly inhibited IL‐4 production of CD4+ T cells from the peripheral blood mononuclear cells of patients with asthma. PS attenuates HDM‐induced asthma via the inhibition of the Glut1/mTOR/GATA3 axis in Th2 cells, which supports the potential pharmaceutical application of PS treatment for asthma.
The inhibition of glycolysis by blocking glucose transportation is involved in pterostilbene's anti‐Th2 and anti‐eosinophil immune responses, which relieve bronchoconstriction. The downregulation of the mTOR‐GATA3 axis contributed to epigenetic changes through histone deacetylation in pterostilbene‐treated Th2 cells and ultimately led to a decrease in IL‐4 and IL‐13.
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